Home Lighting Features of operation and occurrence of malfunctions in the lambda probe. Lambda probe, its malfunctions and methods of checking Symptoms of a dying lambda probe

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Features of operation and occurrence of malfunctions in the lambda probe. Lambda probe, its malfunctions and methods of checking Symptoms of a dying lambda probe

Do you want to know the symptoms of a malfunctioning lambda probe? You have come to the right place. By the way, this site most often worries the minds of owners of foreign cars, but first things first. But in general, the point for which the sensor is used is to probe the exhaust gases.

European automakers, under the yoke of environmentalists and new bills that require limiting the emission of harmful substances into the atmosphere, are resorting to the use of various new units in every possible way. Most often these are various neutralizers or catalysts - devices that actively reduce the amount of harmful substances in the exhaust of a car.

It will be easier to understand the symptoms of a lambda probe malfunction if you know its structure and principle of operation. Catalysts are active devices to deal with harmful substances in the exhaust, but they require constant attention and work only under extremely limited conditions. It also requires careful control over the quality of the air-fuel mixture entering the engine.

Basic functions of a lambda probe

As noted above, for a longer catalyst life, tight control over the quality of the air-fuel mixture is necessary. The lambda probe takes its name from the Greek letter, in the automotive world, this letter marks the coefficient of excess air in the fuel mixture entering the engine.

In general, a high-quality fuel mixture consists of 13 components of air and 1 fuel. Here you need to understand one simple thing, returning to the quality of the catalysts.

The catalysts can only operate within a very narrow range of the correct fuel to air ratio. Small deviations make these devices useless. Therefore, it is so important to observe this proportion to tenths. Now you understand that such accuracy in calculating proportions, tracking processes and catalysts are all the prerogative of foreign cars. Russian cars are not yet operated in such a strict restrictive framework as foreign cars.

Principle of work

Inside the device you can find a galvanic cell consisting of a solid electrolyte inside (zirconia). Various coatings, in the form of conductive materials such as platinum. One of the electrodes is located in the zone of exposure to exhaust gases, and the other is in the ambient air.

The device begins to function correctly only after 350 ° C, only under these conditions the galvanic cell provides the required conduction current.

Malfunctions

(banner_content) The lambda probe performs the complex function of a controller in the exhaust cycle. The easiest way to check the quality of the unit is to measure the exhaust gases. This can be done using a special stand at service stations. If the indicator differs from that declared by the manufacturer, then most likely, the sensor ordered to live long.

Usually, the percentage of rejection of harmful substances can reach up to 4%... This problem can be observed on old engines, where the motor itself is already running with its last bit of strength. Extra additives and additives appear in the fuel mixture. The catalysts do not cope with the work and as a result, the entire system begins to produce an increased amount of pollutants into the atmosphere.

In addition to measuring emissions in the exhaust of a car, there are indirect signs that indicate a malfunction of the probe.

For example, if you notice negative change in the dynamics of acceleration(acceleration has worsened). Also, if the engine starts to run at idle speed, the revolutions jump, the reason may lie in the breakdown of the probe. If you carefully monitor the amount of fuel consumed, then its increase may indicate a known cause. It is recommended to replace the lambda probe on a modern foreign car every 100 thousand kilometers.

Manufacturers note that cars operated in cold conditions without warming up require replacing the lambda probe much more often than warmed-up ones. This indicator can double the difference! Therefore, we strongly recommend warming up the car without load, especially if it has been standing for a long time at very low negative temperatures.

The main reason for the failure of the probe is carbon deposits.... It meets under the protective cap, covering the sensitive areas of this device. By the way, if it is possible to remove carbon deposits, then the unit will start functioning and it will not have to be replaced with a new one (save money).

For cleaning, you can use phosphoric acid by placing the device in it for 15 minutes or better, smearing it on the contaminated area.

Testing the probe

It will not be superfluous if you test this sensor at least every 35 thousand kilometers. If you are measuring, remember that the probe needs time to warm up to operating temperature. The symptoms listed above will help you save time and money. Exhaust gas measurements are carried out by some dealers, where you can get some recommendations.

The oxygen sensor, the symptoms of which are known to most experienced car owners, plays a significant role in the functioning of the car. For all its invisibility and small size, this regulator adjusts the fuel mixture, thereby assisting the power plant.

A car engine that receives a well-mixed air / fuel mixture works as efficiently as possible. Unfortunately, the regulator sensor or lambda probe, as it is also called, tends to deteriorate.

Causes of malfunction and obvious signs

As a rule, the following reasons lead to a malfunction of the sensor:

Any aggressive liquid, such as antifreeze or brake fluid, gets on the sensor.
Problems can begin if the owner has used reactive agents to clean the regulator body.
If the car fuel contains a large amount of lead compounds.
In case of significant overheating of the regulator, which occurs either due to the use of poor quality fuel, or due to clogged filter.

Regulator malfunctions can be judged by obvious signs of an external nature. It's easy to notice. It is enough to pay attention to the following points:

Fuel consumption has increased dramatically.
The car jerks from the spot even when the engine is warm.
The color and smell of the exhaust gases has changed.
The catalyst is malfunctioning.

Of course, the general operating conditions also have a negative impact on the sensor. The electrical wiring or the regulator itself can be damaged if the standard rules of car operation are not followed carefully.

Steps

In turn, experts see two main stages in the deterioration of the sensor.

At the first stage of the sensor malfunction, there is an increase in the engine reaction time to pressing the gas pedal. The power unit reacts sluggishly, when the accelerator is pressed, the "check" starts flashing, the pedal is lowered - the flashing stops. At this stage of the malfunction, the driver notices a deterioration in traction, acceleration dynamics and an increase in fuel consumption (so far insignificant). Typically, this stage of a regulator malfunction can last for about a year.

The second stage is already much sadder. At this stage, most car owners think about why this oxygen sensor is actually needed. Normal acceleration completely disappears, the car “dulls” even on an absolutely flat road. Another distinctive feature of the second stage is a decrease in the speed of the power unit, even when the accelerator is pressed into the floor. This may cause a popping sound in the intake manifold.

For complete confidence, it is recommended to start the car "cold". If the oxygen sensor is faulty on the second scale of severity, the car will work ideally only for the first few minutes. When the device starts to function, sending signals to the ECU, problems immediately arise.

Regulator check

If there is a suspicion of a malfunction of the regulator, it is recommended to start with an assessment of its external condition. In most cases, if the sensor is defective, it will be covered with a layer of dirt or soot. The normal appearance of the sensor, as a rule, indicates its normal operation, but the test should be continued.

The regulator should be disconnected from the block.
Then connect it to a voltmeter with a sufficiently high accuracy class.

Note. The scheme for connecting the regulator to a voltmeter should be based on its pinout: the black wire of the sensor is responsible for the signal (goes to the controller), the white wires are responsible for heating, the gray wire is for grounding.

Checking voltmeter readings is diagnostics based on the dynamics of the vehicle's power plant. For example, if cruise mode (2500 rpm) is enabled, with the vacuum tube removed, the normally operating regulator should output 0.9 V (slightly more or less). If the sensor readings are below 0.3 V, then the device is definitely faulty.

The sensor check can have another mode. It is possible to simulate forced air suction, thereby depleting the air-fuel mixture. In this case, the readings of the regulator should be less than 0.2 V.

Another test mode is related to the intermediate position of the motor. In other words, if the speed of the power plant is within 1500 rpm, the regulator should show a value of 0.5 V.

In case of complete proof of a sensor malfunction, it should be dismantled and replaced. And here you have to adhere to certain rules.

It is better to change the regulator on a running car, so to speak, "to hot". This gives you a better chance of not stripping the threads.
It is also recommended to slightly raise the connector of the new regulator, thereby protecting the device from dirt and moisture.
And finally, experts advise to treat the sensor body with "graphite", even with factory grease.

Almost all modern cars have an oxygen sensor. The device can be located in different ways. On some vehicles it is located near the catalyst, on others in the exhaust manifold.

What to do if a faulty sensor is found on the road

If a sensor malfunction is found on the road or you need to go somewhere urgently, and the problems with the probe have not been resolved, what can be done? The solution is ingenious to simplicity - you just need to disconnect the probe. Of course, the flashing "check" will not disappear anywhere until the engine stops, and the dynamics, in principle, will not be normal. But you can easily get to the car service, albeit without amenities.

You need to install a probe that is recommended by a specific car manufacturer. Putting some kind of "left" device, albeit for the sake of economy, you can expose the engine to unbearable loads and problems. Undoubtedly, engine repairs will cost a lot more than buying a quality oxygen sensor.

Replacing the regulator

Replacing the oxygen sensor on domestic cars, as a rule, does not cause any particular difficulties. The only difficulty may lie in the boiling of the probe, after which it practically does not lend itself to mechanical stress. But even for such cases, there is an effective and step-by-step instruction. It is shown below.

The car rises to the overpass.
The protection of the power unit is removed.
The hood opens, work begins with the probe wires. The oxygen sensor wiring can be found on the CO (cooling systems) hoses. They are fixed with clamps.

The plastic clamp holding the wiring is cut;
The sensor is unscrewed with a key on "22".

If the device cannot be removed, the sensor is boiling. We act according to the following scheme. Sprinkle the regulator with WD-40, wait a bit and try to remove it again. If it doesn't work again, we start the engine and heat up the exhaust system a little, pour water on the regulator and try again. If it does not help, you will have to heat the sensor directly with a soldering iron, knock on it with a hammer (not hard) and unscrew it.

The regulator is installed in the reverse order of removal. Remember to connect the connector and secure the wiring to the hoses.

Knowing the signs of a malfunction of the lambda probe, you can react to this in time and replace it. A normally functioning sensor is a high-quality and trouble-free engine operation. The motorist should never forget this.

It leads to increased fuel consumption, a decrease in the dynamic characteristics of the car, unstable operation of the engine at idle speed, an increase in the toxicity of exhaust gases. Usually, the reasons for the malfunction of the oxygen concentration sensor are its mechanical damage, a break in the electrical (signal) circuit, contamination of the sensitive part of the sensor with fuel combustion products. In some cases, for example, when a p0130 or p0141 error occurs, the check engine warning light is activated on the dashboard. It is possible to use the car with a faulty oxygen sensor, but this will lead to the above problems.

Purpose of the oxygen sensor

An oxygen sensor is installed in the exhaust manifold (the specific location and quantity may differ for different cars), and monitors the presence of oxygen in the exhaust gases. In the automotive industry, the Greek letter "lambda" stands for the excess oxygen ratio in the air-fuel mixture. It is for this reason that an oxygen sensor is often referred to as a "lambda probe".

The information provided by the sensor about the amount of oxygen in the exhaust gas by the electronic engine control unit (ECU) is used to adjust the fuel injection. If there is a lot of oxygen in the exhaust gases, it means that the air-fuel mixture supplied to the cylinders is poor (the voltage at the sensor is 0.1 ... 0.3 Volts), and if there is a lot of oxygen, it means that it is rich (the voltage at the sensor is 0.6 ... 0.9 Volta). Accordingly, the amount of supplied fuel is corrected as needed. This affects not only the dynamic characteristics of the engine, but also the operation of the catalytic converter of exhaust gases.

In most cases, the range of effective operation of the catalyst is 14.6 ... 14.8 fractions of air per one fraction of fuel. This corresponds to a lambda value of one. Thus, the oxygen sensor is a kind of controller located in the exhaust manifold.

Some vehicles are designed to use two oxygen concentration sensors. One is located before the catalyst, and the second is located after. The task of the first is to correct the composition of the air-fuel mixture, and the second is to check the efficiency of the catalyst. The sensors themselves are usually identical in design.

Does the lambda probe affect the launch - what will happen?

If you turn off the lambda probe, there will be an increase in fuel consumption, an increase in toxicity of gases, and sometimes unstable engine idling. However, this effect occurs only after warming up, since the oxygen sensor begins to work under conditions of an increased temperature up to + 300 ° C. For this, its design implies the use of a special heating, which turns on when the engine is started. Accordingly, immediately at the moment of starting the engine, the lambda probe does not work, and in no way affects the start itself.

When the protective cap has been completely dismantled, then argon welding will have to be used to restore it in its seat.

The recovery procedure is performed according to the following algorithm:

Pour 100 ml of phosphoric acid into a glass container.
Immerse the ceramic element of the sensor in acid. Do not completely immerse the sensor in acid! Then wait about 20 minutes for the acid to dissolve the soot.
Remove the sensor and rinse it under running water from the tap, and then let it dry.

Sometimes it takes up to eight hours to clean the sensor using this method, because if the soot is not cleaned the first time, it makes sense to repeat the procedure two or more times, and you can use a brush to perform mechanical surface treatment. You can use a toothbrush instead of a brush.

Method two

Assumes formation of carbon deposits on the sensor. To clean the oxygen sensor with the second method, in addition to the same orthophosphoric acid, you will also need a gas burner (as an option, use a home gas stove). The cleaning algorithm is as follows:

Dip the sensitive ceramic element of the oxygen sensor in acid, wetting it abundantly.
Take the sensor with pliers from the side opposite to the element and bring it to the burning burner.
The acid on the sensitive element will boil, and a greenish salt will form on its surface. However, along with this, the soot will be removed from it.

Repeat the described procedure several times until the sensing element becomes clean and shiny.

Modern vehicles are equipped with a variety of sensors that monitor the performance of components and assemblies. One of the main sensors in a car is the residual oxygen sensor (λ probe). However, only a few motorists know how to check a lambda probe on their own, saving time and money.

What is a lambda probe and where is it located

In connection with the tightening of environmental standards to reduce the toxicity of exhaust gases, cars began to be equipped with a catalytic converter (catalyst). The quality and duration of its operation is directly dependent on the composition of the fuel-air mixture (FA). Depending on the signals transmitted by the lambda probe, the percentage in the mixture of fuel and air is regulated.

Lambda probe is a system that determines how much residual oxygen is contained in the exhaust gases. Otherwise it can be called an oxygen sensor.

The lambda probe is located in the exhaust manifold in front of the catalytic converter

High-quality purification from toxic exhaust in the catalyst is carried out only in the presence of oxygen in them. To monitor the effectiveness of the catalytic converter and improve the accuracy of examining the state of exhaust gases on many models, a second lambda probe is installed at the outlet of the catalyst.

To improve efficiency, an additional lambda probe is installed on the catalyst outlet on modern cars.

How an oxygen sensor works

The main function of the lambda probe is to measure the amount of oxygen contained in the exhaust gases and compare it with the reference.

Electrical impulses from the oxygen sensor are sent to the electronic control unit (ECU) for the fuel system. With respect to these data, the ECU regulates the composition of the fuel assemblies supplied to the cylinders.

Installation diagram of the main and additional oxygen sensors in the car

The result of the joint work of the lambda probe and the ECU is to obtain a stoichiometric (theoretically ideal, optimal) fuel assembly, consisting of 14.7 parts of air and 1 part of fuel, at which λ = 1. For a rich mixture (excess gasoline) λ<1, у обеднённой (избыток воздуха) - λ>1.

Graph of power (P) and fuel consumption (Q) versus value (λ)

Varieties of lambda probes

Modern machines are equipped with the following sensors:

Zirconium;
Titanium;
Broadband.

Zirconium

One of the most common models. Created on the basis of zirconium dioxide (ZrO2).

The zirconium oxygen sensor operates on the principle of a galvanic cell with a solid electrolyte ceramic made of zirconium dioxide (ZrO2)

The ceramic tip with zirconium dioxide is covered on both sides with protective screens made of conductive porous platinum electrodes. The properties of an electrolyte that allow oxygen ions to pass through are manifested when ZrO2 is heated above 350 ° C. The lambda probe will not work without warming up to the desired temperature. Fast heating is carried out due to the heating element with a ceramic insulator built into the housing.

Important! An increase in the temperature of the sensor to 950 ° C leads to overheating.

Exhaust gases enter the outer part of the handpiece through special gaps in the protective casing. Atmospheric air enters the sensor through a hole in the housing or a porous waterproof sealing cover (cuff) of the wires.

The potential difference is formed due to the movement of oxygen ions through the electrolyte between the outer and inner platinum electrodes. The voltage generated across the electrodes is inversely proportional to the amount of O2 in the exhaust system.

The voltage that forms across the two electrodes is inversely proportional to the amount of oxygen

With respect to the signal coming from the sensor, the control unit regulates the composition of the fuel assembly, trying to bring it closer to the stoichiometric one. The voltage supplied from the lambda probe changes several times every second. This makes it possible to regulate the composition of the fuel mixture regardless of the operating mode of the internal combustion engine.

By the number of wires, several types of zirconium devices can be distinguished:

A single wire sensor has a single signal wire. Ground contact is made through the housing.
The two-wire device is equipped with signal and ground wires.
Three- and four-wire sensors are equipped with a heating system, control and ground wires to it.

Zirconium lambda probes, in turn, are divided into one-, two-, three- and four-wire sensors

Titanium

Visually similar to zirconium. The sensing element of the sensor is made of titanium dioxide. Depending on the amount of oxygen in the exhaust gases, the volumetric resistance of the sensor changes abruptly: from 1 kOhm with a rich mixture to more than 20 kOhm with a lean one. Accordingly, the conductivity of the element changes, which the sensor signals to the control unit. The working temperature of the titanium sensor is 700 ° C, therefore a heating element is required. There is no reference air.

Due to its complex design, high cost and fastidiousness to temperature changes, the sensor is not widely used.

In addition to zirconium, there are also oxygen sensors based on titanium dioxide (TiO2)

Broadband

Structurally differs from the previous 2 chambers (cells):

Measuring;
Pumping station.

In the chamber for measurements using an electronic voltage modulation circuit, the composition of gases is maintained corresponding to λ = 1. When the engine is running on a lean mixture, the pumping cell removes excess oxygen from the diffusion gap into the atmosphere; with a rich mixture, it replenishes the diffusion hole with missing oxygen ions from the outside world. The direction of the current for moving oxygen in different directions changes, and its value is proportional to the amount of O2. It is the current value that serves as the detector λ of the exhaust gases.

The temperature required for operation (at least 600 ° C) is achieved through the operation of a heating element in the sensor.

Broadband oxygen sensors detect lambda from 0.7 to 1.6

Malfunction symptoms

The main signs indicating a breakdown of the oxygen sensor are:

Increased toxicity of exhaust gases;
Unstable, intermittent acceleration dynamics;
Short-term switching on of the "CHECK ENGINE" lamp with a sharp increase in revolutions;
Unstable, constantly changing idle speed;
Increased fuel consumption;
Overheating of the catalyst, accompanied by crackling sounds in its zone when the engine is turned off;
Constantly lit indicator "CHECK ENGINE";
Unreasonable signaling of the on-board computer about an over-enriched fuel assembly.

It must be borne in mind that all these deviations can be symptoms of other breakdowns.

The service life of the lambda probe is approximately 60-130 thousand km. The reasons for the reduction in the service life and breakdown of the device can be:

Application when mounting sensors that are not designed for high temperatures of sealants (silicone);
Low-quality gasoline (high content of ethyl, lead, heavy metals);
Oil entering the exhaust system as a result of wear on the oil scraper rings or seals;
Overheating of the sensor as a result of an incorrectly set ignition, over-enriched fuel assembly;
Multiple attempts to start the engine, leading to the penetration of combustible mixtures into the exhaust system;
Unstable contact, short to ground, break in the output wire;
Violation of the integrity of the sensor structure.

Oxygen sensor diagnostic methods

Experts advise checking the correct operation of the lambda probe every 10,000 km, even if there are no problems in the operation of the device.

Diagnostics begin with checking the reliability of the connection of the terminal with the sensor and for the presence of mechanical damage. Next, unscrew the lambda probe from the manifold and inspect the protective casing. Small deposits are cleaned.

If, during a visual inspection, traces of soot, strong white, gray or shiny deposits are found on the protective tube of the oxygen sensor, then the lambda probe should be replaced.

How to check a lambda probe with a multimeter (tester)

Checking the sensor for operability is carried out according to the following parameters:

Heating circuit voltage;
"Reference" voltage;
Heater state;
Sensor signal.

Connection diagram to the lambda probe, depending on its type

The presence of voltage in the heating circuit is determined with a multimeter or voltmeter in the following sequence:

Without removing the connector from the sensor, turn on the ignition.
The probes are connected to the heating circuit.
The readings on the device must match the voltage on the battery - 12V.

"+" Goes to the sensor from the battery through the fuse. In his absence, this circuit is called.

"-" comes from the control unit. If it is not found, check the terminals of the "lambda probe - ECU" circuit.

Measurements of the reference voltage are carried out with the same devices. Sequencing:

Switch on the ignition.
Measure the voltage between the signal wire and ground.
The device should show 0.45 V.

To check the heater, the multimeter is set to ohmmeter mode. Diagnostic steps:

Remove the connector from the device.
Measure the resistance between the heater contacts.
The readings on different oxygen tanks are different, but should not go beyond 2-10 ohms.

Important! The absence of resistance indicates an open circuit in the heater circuit.

A voltmeter or multimeter is used to check the sensor signal. For this:

Start the engine.
Warm it up to operating temperature.
The probes of the device are connected to the signal wire and the ground wire.
The engine speed is increased to 3000 rpm.
Monitor voltage measurements. There should be jumps in the range from 0.1 V to 0.9 V.

If at least during one of the checks the indicators differ from the norm, the sensor is faulty and needs to be replaced.

Video: checking the lambda probe with a tester

The main advantage of this diagnostics of the lambda probe over checking with a voltmeter and a multimeter is the time fixation between similar changes in the output voltage. It should not exceed 120 ms.

Sequence of actions:

The probe of the device is connected to the signal wire.
The motor is warmed up to operating temperature.
The engine speed is increased to 2000-2600 rpm.
According to the readings of the oscilloscope, the operability of the oxygen sensor is determined.

Oscilloscope diagnostics gives the most complete picture of the operation of the lambda probe

Exceeding the time limit or crossing the voltage limits of the lower 0.1 V and upper 0.9 V indicates a faulty oxygen sensor.

Video: diagnostics of an oxygen sensor with an oscilloscope

Other ways to check

If the car has an on-board system, then by the "CHECK ENGINE" signal, which generates a certain error, it is possible to diagnose the state of the lambda probe.

List of lambda probe errors

In order for the lambda probe to work for a long time and efficiently, it is necessary to fill the car with only high-quality fuel. Scheduled and timely diagnostics of the oxygen sensor will help detect its malfunction in time. This measure is able to extend the life of not only the sensor itself, but also the catalyst.

The purpose of the lambda probe (oxygen sensor) is to transmit information about the composition of the working mixture from the exhaust manifold to the ECU. The combustion quality of the fuel-air mixture (FA) directly affects the operation of the engine.

On modern cars with an injection engine, one or more catalysts and two or more oxygen sensors are installed. Where is the lambda probe located? Depends on the type of car. Systems with two devices, which are located before and after the catalyst, are common. Thus, the excess of oxygen in the mixture is determined before the gases enter the device. On vehicles with one probe, it is installed at the front, on the exhaust manifold.

How an oxygen sensor works

The ECU measures the amount of fuel supplied using the injectors, setting the volume at a certain moment. The probe provides feedback that allows you to accurately determine the proportions of petrol, diesel or gas. The ECU requests information once every 0.5 seconds at idle speed. At higher speeds, the frequency of requests increases proportionally. Analyzing the data, the control unit adjusts the composition of the fuel assembly, making it poorer or richer. Maintaining an optimal fuel assembly - the appointment of lambda probes. The ideal air to fuel ratio is considered to be 14.7: 1 (petrol), 15.5: 1 (gas) and 14.6: 1 (diesel).

Point-to-point, narrowband (simple). Works based on measuring the amount of oxygen in the exhaust gas. The poorer the fuel assembly, the lower the voltage, the richer - the higher.

The average lifespan of oxygen sensors on Russian gasoline is 40,000-100,000 km. To increase the service life, it is recommended to fill in high-quality fuel with a low content of impurities and heavy metals. It is quite difficult to determine the malfunction by self-diagnosis, it is almost impossible to establish the cause. This can be wear, poor quality gasoline, mechanical damage and other factors.

Short circuit in the wiring;
Ignition misfires;
Normal wear and tear. In conditions of low-quality fuel, the average sensor service life is 40-70 thousand km.

Fuel consumption increases. Each motorist monitors the fullness of the tank, tries to find his own cruising speed when the fuel consumption is minimal. Therefore, the increased fuel consumption will be noticed immediately. Depending on the severity of the lambda probe malfunction, it grows by 1-4 liters. The increased consumption, of course, can cause not only a faulty oxygen sensor.

How to check a lambda probe

The procedure is as follows:

Test the probe signal with a motor tester, dial voltmeter or oscilloscope. Connect a tester between the ground wire and the signal wire, raise the speed to 3,000 Nm, note the time and follow the readings. They should vary from 0.1 to 0.9 volts. We recommend replacing the sensor if the range of changes is less or less than 9-10 readings changed in 10 seconds. The reason for the error may be "fatigue" and slow response of the system.

Video instruction:

Correct operation of the oxygen sensor helps:

Increase the performance of the engine by determining the proportion of injected fuel and air close to the ideal.
Reduce the production of harmful gases (CO, CH, NOx) emitted into the atmosphere and improve the economical operation of the car due to the correct composition of the working mixture.

How an oxygen sensor works

Types of oxygen sensors by design and principle of operation:

Point-to-point, narrowband (simple). Works based on measuring the amount of oxygen in the exhaust gas. The poorer the fuel assembly, the lower the voltage, the richer - the higher.
Broadband. Generates a signal of a wider range for an accurate estimate of the proportion in fuel assemblies.

The average life span of oxygen sensors running on Russian gasoline is 40,000–100,000 km. To increase the service life, it is recommended to fill in high-quality fuel with a low content of impurities and heavy metals. It is quite difficult to determine the malfunction by self-diagnosis, it is almost impossible to establish the cause. This can be wear, poor quality gasoline, mechanical damage and other factors.

If you have any suspicions about a malfunction of the oxygen sensor, contact a professional diagnostician. Using the oscillogram, the specialist will determine the causes of the malfunction and suggest remedies.

What causes the lambda probe to fail

Mechanical damage. Severe impact as a result of an accident, collision with a curb or off-road driving adversely affects the condition of the probe;
Incorrect engine operation and malfunctions of the ignition system lead to overheating of the oxygen sensor and breakdown;
Clogged system. The main reason for the malfunction of the lambda probe will be the combustion products of low-quality fuel. The more heavy metals, the sooner it clogs;
Breakage in the piston group. Defective piston, gudgeon pin and connecting rod leak oil into the exhaust system, which clogs the probe;
Liquid ingress. Contamination of any kind will shorten the life of the probe;
Short circuit in the wiring;
Too rich or poor air-fuel mixture;
Depressurization of the exhaust system allows air and exhaust gases to pass through, which disables the lambda probe;
Ignition misfires;
Fuel additives and "improvers";
Normal wear and tear. In conditions of low-quality fuel, the average sensor service life is 40–70 thousand km.

Failure of the lambda probe occurs gradually. The consequences of a faulty oxygen sensor result in an emergency engine control mode. This is how manufacturers protect the car from serious breakdowns, and the driver from emergencies.

Symptoms of a malfunctioning lambda probe

The level of toxicity of gases increases. To determine toxicity, you can use diagnostics. Outwardly, it is not diagnosed in any way, even the smell of the exhaust will practically not change.
Fuel consumption increases. Each motorist monitors the fullness of the tank, tries to find his own cruising speed when the fuel consumption is minimal. Therefore, the increased fuel consumption will be noticed immediately. Depending on the severity of the lambda probe malfunction, it grows by 1-4 liters. The increased consumption, of course, can cause not only a faulty oxygen sensor.
Oxygen sensor errors are issued (P0131, P0135, P0141 and others), "Check Engine" lights up. Usually a check appears when the probes or catalyst are faulty. Diagnostics will establish the exact cause.
The catalyst is overheating. Defective lambda probes give incorrect signals to the ECU, which can lead to incorrect operation of the catalyst, its overheating up to a red-hot state, and subsequent failure.
Twitching and uncharacteristic pops appear in the engine. Lambda probes stop generating the correct signal, which destabilizes the idle speed. The revs fluctuate over a wide range, which leads to a deterioration in the quality of the fuel mixture.
The dynamic characteristics of the car deteriorate, power and traction are lost. Similar signs appear in advanced situations. Defective sensors also stop working on a cold engine, and the machine signals a system problem in various ways.

If you are concerned about one of these signs, see a specialist. With the help of diagnostic equipment, he will determine the exact area of the breakdown and help in fixing it.

How to check a lambda probe

So, the car is jerking, fuel consumption has increased, "Check Engine" is on. Signs are not characteristic only of lambda breakdowns, therefore, a complete system diagnostics is needed. But if you are sure that this is the case, we will tell you how to check the sensor with your own hands.

The procedure is as follows:

Warm up the engine to operating temperature. An unheated lambda probe will not work.
Remove and inspect the probe and wiring for mechanical damage and contamination. If it is bent, scratched, or covered with soot build-up, lead deposits, white or gray carbon deposits, replace.
Check the operation of the lambda probe with an ohmmeter. Often the cause of the malfunction lies in the breakdown of the heating coil or wires to it. How to "ring" him? Connect an ohmmeter between the heater wires, previously disconnected from the block. With proper operation, the resistance of the signal circuit on different vehicles varies from 2 to 10 ohms and from 1 kΩ to 10 mΩ in the heating circuit. If it is not there at all, there is an open circuit in the wiring.
Test the probe signal with a motor tester, dial voltmeter or oscilloscope. Connect a tester between the ground wire and the signal wire, raise the speed to 3,000 Nm, note the time and follow the readings. They should vary from 0.1 to 0.9 volts. We recommend replacing the sensor if the range of changes is less than or in 10 seconds less than 9-10 readings have changed. The reason for the error may be "fatigue" and slow response of the system.
Check the health of the lambda probe through the reference voltage. Start the car, measure the voltage between ground and signal wire. If the readings differ from 0.45 volts by more than 0.2, the sensor or circuits in the circuit leading to it are faulty.

If there are no devices for testing the performance of the lambda probe, contact a specialist. They will carry out a full diagnosis and accurately name the cause of the malfunction for less money and time that you would spend on buying devices and troubleshooting yourself.

Video instruction:

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