A lambda probe is an oxygen sensor. The Greek lambda in mechanical engineering means the ratio of excess air in the fuel-air system. A breakdown of this device can have extremely negative consequences for the engine and the entire vehicle. Therefore, it is very important to know how to determine the malfunction of the lambda probe.
The purpose
The lambda probe measures the amount of oxygen in the residual gases. The collected data is transferred to the engine ECU. This allows you to determine the nature of fuel combustion. It is impossible without this stable work catalytic converter.
The catalyst efficiency window is very small. Therefore, it is so important to identify the signs of a malfunction of the lambda probe in advance. After all, it is this device that is responsible for monitoring the exhaust tract.
Important! The device is only available in systems with electronic injection.
To understand why the lambda probe broke, you need to understand a little about its design. It is installed in the exhaust tract, close to the catalyst. If the system meets the Euro 3 standard, then there must be another device at the output.
Diagnostics
Attention! To determine most of the signs of a malfunction of the lambda probe, a high-quality technical diagnostics... It is recommended to check it once every 30 thousand kilometers.
The main indicator of a malfunctioning lambda probe is an incorrect output voltage. At Idling at 2000 rpm. This indicator should be in the range from 0 to 1 V.
To measure the residual oxygen in the used gases, the temperature must be 300-400 degrees. At this temperature, the zirconium electrolyte acquires conductivity. The difference between atmospheric oxygen and oxygen in the exhaust pipe leads to the appearance of a voltage at the electrodes of the lambda probe.
Therefore, to check for faults, diagnostics are carried out with the engine running. All measurements are carried out using a multimeter or oscilloscope.
At the end of the troubleshooting procedure, the resistance of the sensor heater is measured. Disconnect the plug before checking. Standard from 2 to 14 ohms. Usually the manufacturer sets the standards for his lambda probes himself. Voltage is also checked. The recommended indicator is 10, 5 V.
Attention! A lower reading indicates a malfunction. Checking the battery voltage, connection and cable voltage can help.
Malfunction symptoms
There are certain symptoms that make it possible to determine in advance the malfunction of the lambda probe. If your engine stops working stably, the sensor may be the cause.
If the lambda probe is faulty, the quality of the pumped fuel mixture deteriorates. Feeding becomes uncontrolled and ineffective. Typically, the recovery of the device from normal operating mode occurs gradually. As a result, it is extremely difficult to notice a malfunction in the early stages of the process.
Any serious lambda probe malfunction begins with an unstable signal transmission to certain engine compartments. Naturally, idling goes wrong.
The revolutions fluctuate in a fairly wide range, which leads to a decrease in the quality of the fuel system and the efficiency of the entire engine. One of the signs of serious damage to the lambda probe is the constant "jerking" of the car.
Incomprehensible pops are heard when the engine is running. A light on the instrument panel flashes constantly, signaling a malfunction of the lambda probe. The complex of these phenomena clearly demonstrates that something is wrong with the sensor. If nothing is done now, then soon the device will completely fail.
Attention! An important bell and a sign of a serious malfunction is a drop in power.
The next stage of the lambda probe malfunction is the final breakdown. In addition to the drop in power, there is a slow response of the system when the accelerator pedal is pressed. Pops are constantly heard from under the hood. The car "jerks".
Attention! Another important symptom of a malfunctioning lambda probe is engine overheating.
What happens if you ignore the symptoms of a malfunction?
Naturally, every driver is interested in what the malfunction of the lambda probe affects. Most often, when a given part fails, the following consequences can be observed:
- The vehicle is moving unnaturally.
- Increases at times fuel consumption.
- An unpleasant, pungent odor arises from the exhaust pipe.
In modern cars with electronic filling, in the event of a breakdown of the lambda probe, emergency blocking is immediately activated. This allows you to save the car from serious breakdowns even if the driver did not notice any signs of malfunction. In addition, driving with a broken lambda probe is simply unsafe.
The car is behaving too unpredictably. Because of this, an emergency situation on the road may arise, which will endanger not only the life of the driver, but also the lives of other people. That is why it is so important to notice the signs of a malfunction in time and send the car to the service. Moreover, for greater safety, it is better to call a tow truck.
In the worst case scenario, the sensor is depressurized. In such a case, further movement may damage the engine. To recover, you will need at least overhaul.
When depressurization occurs, exhaust gases enter the intake duct. When braking, the lambda probe begins to fix a huge number of oxygen molecules. As a result, the injection system completely fails.
The main symptom of such a malfunction is power loss. This is best seen at high speeds. At the same time, mechanical tapping under the hood is constantly heard. Bad smell and jerks are also present.
Advice! In order to be sure of a malfunction of the lambda probe, open the hood and inspect the valves. Sediment from soot formations will be a sign of breakage.
Causes
It is best not to troubleshoot vehicle malfunctions, rather than let them occur. There are a number of reasons that can lead to a breakdown of the lambda probe, the main ones are:
- Bad gasoline... Excess impurities clog the platinum electrodes.
- The unsatisfactory condition of the oil scraper rings.
- Hit vehicle in an accident.
- Contact with the ceramic tip with solvents or antifreeze.
- Overheating of the lambda probe housing. This is due to an incorrectly set ignition timing.
- Bad contact of the output circuit of the sensor.
- Malfunctions in the ignition system.
- Repeated attempts to start the engine with short rest periods. This causes unburned fuel to build up in the exhaust pipe and can ignite.
Important! Under no circumstances should sealants be used when installing the lambda probe, which tend to cure. Also, they should not contain silicone.
The sensor resource is on average estimated at 30-70 thousand kilometers. Much depends on the manufacturer and the operating conditions of the vehicle. That is why it is so important to know the signs of possible breakdown. This information will help you to always be on the alert and prevent more serious malfunctions.
According to statistics, heated lambda probes have a longer service life. It is not surprising that the main symptom of a malfunction of such a device is the inoperative heating. Also performance decreases.
Advice! If you notice any of the above, use an oscilloscope to confirm. The device can be bought for 4000-5000 rubles.
Buying an oscilloscope allows you to save your car from a malfunction of the lambda probe and costly repairs. If you do not want to do the diagnostics yourself, just take the car to the service, the check procedure will not take much time.
Lambda probe malfunctions in the "Lada" Kalina
Unfortunately, domestic car already famous for the many malfunctions of the lambda probe. The signs of breakage are no different from the standard ones, but the reasons are largely due to a not entirely practical design.
Important! In most cases, the heating element breaks in the Kalina lambda probe. In addition, water, dirt or grease often gets on the sensor, which also leads to a malfunction.
If, while driving, you notice the symptoms of a malfunction described in the previous sections. There is a simple and reliable way to check the Kalina lambda probe without additional equipment... Just turn off the ignition, disconnect the harness connector and check contact X1 / C4. If closures with onboard network did not happen - the device is faulty.
Outcomes
Knowing the signs of a malfunction of the lambda probe will allow you to diagnose the breakdown in time and take all the necessary actions to quickly restore the vehicle's performance.
Oxygen sensor is a device in the exhaust manifold of the engine internal combustion, which allows you to estimate how much free oxygen is left in the exhaust mixture.
This sensor also has another name. Lambda probe what is this design and where did this name come from. The sensor is based on a solid ceramic electrolyte made of zirconium dioxide, which in turn is coated with yttrium oxide. Above all, porous, conductive platinum electrodes were deposited on the ceramic element.
Its principle of operation is like that of a galvanic cell. Once installed in the exhaust manifold, it heats up in the flow exhaust gases up to 300 - 400 degrees. It is in the heated state that the zirconium electrolyte acquires conductivity and ensures its normal functioning. A lambda probe is installed in such a way that one of the electrodes breathes outside air, the other with a mixture of exhaust gases. When the amount of oxygen changes on one of the electrodes, a potential difference arises, which is transmitted as a signal to the engine control system, which regulates the fuel supply for injection.
In the science of the ratios of elements in nature, stoichiometry, lambda means the ratio of the actual amount of air to the required one.
Theoretically optimal ratio- this is when the lambda is equal to 1, that is, there is as much real air in the mixture as needed.
If lambda is greater than one- this is poor mix if this value is less than one - a rich mixture, that is, there is an excess of gasoline in the mixture, there is not enough oxygen to burn it.
For power unit the car is considered optimal lambda equal to 14.7: 1, that is, a lean mixture. This is due to the fact that a certain amount of oxygen is required for efficient combustion of CO and CH on the catalyst. The modern lambda probe VAZ 2114 works as a threshold element.
Oxygen sensor VAZ 2114, design and application features
Since the oxygen sensor is turned on after heating the working element to 350 degrees, the first samples were tried to be placed as close as possible to the exhaust manifold. Over time, the sensor was modernized and a heating element was built into it, which brought it into operation much faster and now, the question - where is the lambda probe in the exhaust system, is not so important. Structurally, a modern oxygen sensor consists of the following elements.
- Ceramic tips with protective screens and holes for sampling, on one side of the exhaust gases, on the other - atmospheric air, enclosed in the middle part in a ceramic insulator. They are the main working element of the entire device. These are exactly the electrodes from which the potential difference is removed.
- A conductive heating element is located inside these tips.
- In the middle part there is an electrical signal collector.
- All elements, with the exception of the sensitive parts of the ceramic tips, are enclosed in a threaded metal case, which is designed to fix the sensor in the receiver tube.
- Currently, modern sensors are equipped with a set of wires secured with a sealing collar. Such sensors are called a four-wire lambda probe. Two white wires are contacts of the heating system, one black - signal and black (or white) with a strip - "ground". In earlier samples that are still used today, the potential difference was determined between the wire that went from the sensor to the ECU and the ground on the sensor body. For this, the sensor was smeared with a specific conductive grease before screwing in the place of attachment. However, the high temperature burned out the grease and the sensor's sensitivity suffered. Now this drawback has been eliminated.
The set of wires for the oxygen sensor at its other end, through the plug box, is connected to the electronic on-board device, which requests data from the lambda probe about the state of the mixture with a frequency of 2 times per second at idle speed and more often with increasing speed. Analyzing the obtained data on the presence of oxygen in the exhaust gas mixture, the ECU adjusts the amount of fuel injected into the engine, making the mixture richer or leaner, depending on the incoming oxygen sensor signals. He strives for the optimal value of 14.7: 1, which is laid down in his program.
The performance of the sensor is verified by testing with a meter. The lower signal level should be 0.1 - 0.2 V, the upper one - within 0.8 - 0.9 V. The guaranteed performance of these sensors is very high. Symptoms of a malfunction of a lambda probe manufactured in accordance with GOST begin to appear not earlier than after a run of 80 thousand kilometers, and on average they can withstand a load of 160 thousand kilometers. However, according to the service book, VAZ 2114 is recommended after a run of 80 thousand km. The fact is that although it continues to maintain its performance, its sensitivity is still significantly reduced, which means that fuel consumption indicators deteriorate, for example.
How does the lambda probe affect the operation of the engine, signs of its malfunction
The oxygen sensor lambda probe has a direct effect on the stable operation of the engine, maintaining the correct mixture for the engine operation:
- the engine is stable, without hesitation, idling;
- at hard pressing the gas pedal, there is a timely restructuring in the power supply of the engine with a mixture corresponding to the changing speed, therefore there are no jerks and triplets;
- the best burned exhaust gases are emitted into the atmosphere, due to the efficient operation of the catalyst, which performs afterburning harmful substances in the exhaust pipe.
To provide normal conditions for the sensor to work and to extend its resource, a number of conditions must be observed:
- Use only the gasoline recommended for the VAZ 2114.
- When working with additives, check their quality and permission for use.
- Never use sealants for fixing the sensor, especially silicone.
- Avoid multiple startup attempts in a short period of time.
- Do not disconnect spark plugs when checking cylinder operation.
- To prevent overheating of the exhaust system due to the accumulation of unburned fuel in it, the sensor can withstand temperatures only up to 950 degrees.
- Do not wash the tips with any of the chemically active liquids.
- Make sure that the tightness is maintained at the junction of the sensor with the pipe.
Signs by which you can determine that you need to replace the VAZ 2114 oxygen sensor can be:
- on low gas the engine runs unstably, the speed floats or the engine stalls;
- there is a steady increased consumption fuel in standard conditions;
- there was a deterioration in the dynamic characteristics of the car;
- characteristic crackles in the catalyst area after the engine is turned off, as well as the specific smell of rotten eggs due to the ingress of a large amount of unburned gasoline into the catalyst;
- signal on the on-board computer about errors associated with refusals in the operation of the lambda probe.
Most often, with a faulty oxygen sensor, all of the above signs should appear, and when a situation arises with its replacement, the question will arise which oxygen sensor is on the VAZ 2114. Depending on the year of manufacture of the car in the exhaust system, there can be both single-wire sensors with a mass from the body, so and four-wire. The price of a VAZ 2114 lambda probe in this case can range from 1200 to 3000 thousand rubles.
When replacing the sensor, check it by testing it on an appropriate device, the contacts in the heating line may be damaged, and then the oxygen sensor can be repaired.
If, after removal, a strong carbon deposit is found on the sensor and it shows that the potential difference is not very different from the permissible ones, then this carbon deposit can be removed. To do this, heat the sensor very much, and then cool it down sharply. The carbon deposit should crack and fly around, wrap it with a soft bone.
Some motorists ask car mechanics how to turn off the VAZ 2114 lambda probe. The procedure itself is simple, but the need for this is in great doubt. In this case, the ECU begins to supply gasoline for injection in averaged values and this will immediately affect the stable operation of the engine, increase fuel consumption and deteriorate exhaust characteristics. Not to mention the need for a flashing on-board computer, since it will constantly give an error associated with the absence of an oxygen sensor.
The efficiency of a car engine depends on the quality of combustion of the gas-air mixture. The exact proportions, and accordingly the rational effect of work, are regulated by an oxygen sensor - a lambda probe. Understanding the design and principle of operation of the device is necessary for self-determination and correction of defects. The safety of operation of your own car depends on how quickly the causes / consequences of a malfunction of the lambda probe are identified and eliminated.
Only vehicles with injection engines... Location in the exhaust pipe after the catalytic converter. A dual configuration oxygen sensor can be located upstream of the catalyst, providing enhanced control over the gas composition, thereby enabling more efficient instrument operation.
Operating principle:
- The electronics of the car, which is responsible for the dosage of fuel, sends a signal about the demand for supply to the injector.
- Accordingly, the oxygen device determines the right amount of air to form the correct mixture composition.
- The settings of the device allow you to comply with the requirements for the environmental and economic component of the issue of operating a car - to exclude excessive consumption of fuel and gas pollution of the environment.
Modern cars are equipped with advanced devices - catalysts and paired sensors - which help to reduce the negative effects of exhaust emissions and the consumption of expensive fuels and lubricants. However, in the event of a breakdown of an expensive version of the sensor, "treatment" will cost a considerable amount.
Lambda probe design
Externally, the device looks like a steel elongated body-electrode with output wires and platinum-plated. Internally, the device is as follows:
- A contact that connects wires to an electrical element.
- Dielectric seal for safety with air inlet.
- A hidden zirconium electrode enclosed in a ceramic tip, heated under current up to 300-1000 degrees.
- Protective temperature shield with exhaust gas outlet.
Sensors can be point-to-point or broadband. The device classification does not affect the external and internal organization however, makes a significant difference in how it works. The device described above is a two-point one, the second is an upgraded version.
More about him:
In addition to the two-point design, the sensor also contains an injection element. The meaning of the work is that when the constant voltage fluctuates between the electrodes, a signal is sent to the control unit. The supply of current to the pumping element is increased or decreased, a portion of air enters the analysis gap, where the level of concentration of exhaust vapors is determined.
Symptoms of a malfunction of the lambda probe
Eternal, created by human hands - does not exist. Any technique designed for subtle analysis is capable of failing for many reasons. Oxygen sensors are no exception.
Let's consider in detail:
- Increased CO level. Determine the concentration on your own, perhaps only with the help of instruments. Almost always, the indicators indicate a malfunction of the probe.
- Increased fuel consumption. Injection vehicles are equipped with a display indicating the amount of fuel consumed. Also, the increase can be judged if the refueling frequency exceeds the usual one.
- The light signaling, oriented to the operation of the lambda probe, is constantly on. This is a light bulb Check Engine.
In addition to the described signs of destabilization of the oxygen sensor operation, the quality of the exhaust gas can be assessed visually - light smoke indicates air oversaturation in the mixture, clouds of thick black smoke - on the contrary, excessive fuel consumption.
Reasons for the breakdown of the oxygen sensor
Since the device directly works with fuel combustion products, the quality of it (fuel) cannot but affect the productivity and result. A combustible product that does not meet all established GOSTs and regulations often serves as the primary reason why the sensor does not show reliable results or, in general, fails. Lead is deposited on the surface of the electrodes, making the lambda probe insensitive to detection.
Other reasons:
- Mechanical failure... From vibration and / or active use of the car, the sensor body is damaged. The device cannot be repaired or replaced. It will be much more rational to purchase and install a new one.
- Incorrect operation of the fuel system... Over time, the soot formed as a result of incomplete combustion of the fuel settles on the housing and gets inside the inlet holes of the probe. The readings become incorrect. The problem is initially stopped by timely cleaning, however, if it occurs constantly, then it will not be possible to get rid of it - the oxygen sensor is a consumable part that must be replaced in a timely manner.
To achieve the serviceability of the car at all its nodes, it is important to send your own "horse" for periodic diagnostics to identify problems. Then, the functionality of the devices, including the lambda probe, will be preserved.
How to independently check a lambda probe for serviceability
Only qualified diagnostics can give a reliable result about the cause of the breakdown. However, it is possible to understand that the sensor is faulty on your own. For this:
Learn the manual. The supplied instructions for the device contain the parameters of the oxygen sensor. It is important to focus on them.
- Opening and inspecting engine compartment find the probe. External contamination in the form of soot and / or light deposits will indicate lead deposition and abnormal fuel system performance. In this case, the device is completely changed and other parts of the car are diagnosed, since the ingress of dirt and heavy metal on them does not bode well.
- If the tip is clean, continue the test. For this, the sensor is disconnected and connected to a voltmeter. The car is started, increasing the speed to 2500 / min and reduced to 200. The readings of the working sensor vary in the range of 0.8–0.9 W. Lack of response or lower values indicate a malfunction.
You can also check the probe using a lean mixture, provoking a suction in the vacuum tube. In this case, the voltmeter readings with a working device are low - up to 0.2 W and below.
The dynamic indicators of a 0.5 W sensor connected to the fuel supply system in parallel with a voltmeter indicate the operability of the device. Other values will indicate a malfunction.
DIY oxygen sensor trick
By avoiding delaying regular maintenance - in particular, for a lambda sensor, it occurs every 30 thousand km - the owner of the car ensures uninterrupted operation of the device. After 100 thousand km, he needs a complete replacement.
If everything is in order with a conscientious attitude to the car, then it will not be possible to control the quality of the fuel. As a result, carbon deposits or lead deposits will cause the light to constantly react. Check indicator Engine. So that the car owner does not bother with this, the problem is solved with the help of a trick.
Types of structures
Depending on financial capabilities, they make bronze spacer parts with their own hands, buy technological electronic options, arrange a flashing of the entire control unit. Let's describe each method in detail:
Homemade device
The body is a bronze piece with high resistance to temperature. The dimensions are strictly matched to the sensor in order to avoid the leakage of exhaust fumes. The hole for their exit into the spacer is no more than 3 mm.
The principle of operation of the device is as follows: ceramic chips inside the cylinder, covered with a catalyst layer under the influence of exhaust gas and oxygen, is oxidized, which causes the concentration to decrease, and the sensor takes the value as normal. The budget option, however, is unacceptable for cars of a high price category - in the end, the automation should work for the result.
Electronic snag
Specialists in soldering circuits can "bungle" a snag for an oxygen sensor with their own hands. This requires a capacitor or resistor. The motorist, whose knowledge is limited, cannot use the method - a lack of understanding of the processes threatens to negatively affect the entire control unit. To resolve the issue, a ready-made structure is purchased. The principle of operation of the emulator with a microprocessor is as follows:
- The microcircuit evaluates the gas concentration and analyzes the signal from the first sensor.
- After that, it generates an impulse corresponding to the signal from the second.
- As a result, average readings are obtained without affecting normal work the control unit, since the input value is always less than the critical one.
Flashing
Deceive oxygen lambda sensor, possibly using a cardinal flashing of the control unit. The bottom line is that there is no reaction to the signal after the catalyst - the sensor only reacts to the state of the unit installed in front of the catalyst, that is, where exhaust vapors are absent or present in a small amount that does not affect the analysis result.
Attention! Warranty services will refuse to do the work, as this contradicts the normal maintenance of the car - any unit must work and respond to emergency situations.
This is especially true for new cars. Therefore, the firmware is purchased independently - by no means via the Internet - or installed by home-grown craftsmen. Otherwise, the damage caused to the car in the future should not cause bewilderment to the owner of the car.
Video review of deception
Determine the malfunction of the lambda probe video
Briefly:
Decreased compression in cylinders, increased wear of compression rings and cylinders and, as a result, reduced engine life. Failure of spark plugs.
Guaranteed failure of the catalyst, the 2nd lambda probe if you continue driving with a faulty 1st lambda probe.
Deterioration of engine cold start, uncomfortable driving, accompanied by reduced power and floating idle and sometimes dips at rpm from 2000 to 3000.
Increased fuel consumption, on average by 5-20% of the usual and even up to 50% in severe cases, which ultimately will result in a year just in the cost of a brand new lambda probe.
A malfunctioning Check Engine light that simply adds anxiety to your life and behind which you can view another malfunction.
More details:
When any malfunction occurs modern car it is necessary to hurry with its elimination, preferably abandoning further intensive operation until it is eliminated. This applies to lambda probes more than to any other part. As already known from the article "What is a lambda probe for?" , this sensor, together with the catalyst, is responsible not only for cleaning the exhaust gases from harmful impurities, but also for the correct mixture formation in the combustion chambers. It sounds innocent enough, and many car enthusiasts believe that after the failure of the oxygen sensor, all that threatens them is an increase in harmful impurities in the exhaust system. However, this is not the case.
Let's try to figure out what happens to the engine and its systems while continuing to operate a car with a faulty oxygen sensor using the example of two main threats.
Reduced engine life.
Let us briefly describe the mechanism of this process, which develops in two directions.
As a result of a sensor malfunction or its incorrect operation under the influence of external factors, an over-enriched fuel mixture... This mixture does not completely burn out, as a result of which the electrodes and insulators of the spark plugs and combustion chambers are covered with black carbon deposits. Heavy carbon deposits carbonize the compression rings of the cylinders. There is an incomplete fit and a decrease in compression, as a result of which part of the gases enters the crankcase and "poisons" the oil.
But this is still not as dangerous as the process going in parallel with the above. The remnants of unburned fuel that penetrated the compression rings wash off the oil film from the cylinder surface, dry friction occurs, leading to a reduction in its resource, and in advanced cases, to engine overheating.
Failure of the catalyst and the 2nd lambda probe.
As we have already found out, in exhaust pipe exhaust gases enter with fuel residues. As a result, the catalyst starts to work in emergency mode, afterburning the remaining fuel. Gradually, the catalyst is destroyed, the products of its destruction begin to clog its honeycomb. The catalyst begins to overheat and melts, permanently sealing its entire honeycomb structure. As a result, the engine power finally drops and the car stops driving due to the fact that there is no place for a free exhaust gas outlet. During this process, the 2nd lambda probe is also poisoned.
Another important reason why the oxygen sensor should be replaced faster is the need to extinguish the burning Check Engine light, because behind the error of the lambda probe, you can overlook the appearance of another error.
During the operation of the car, various malfunctions occur in the fuel system. You can determine the malfunction by paying attention to the behavior of the car in road conditions. But first you need to figure out what types of fuel systems are, from what units and parts it consists.
Types of fuel systems
There are diesel and gasoline engines. They run on different fuels, respectively, they have different fuel systems.
Have diesel engines fuel from the tank through the pipes by the fuel pump is supplied to the high pressure fuel pump (high pressure fuel pump), then from the high pressure fuel pump to the injectors. From the injectors, fuel enters the cylinder directly through the engine intake manifold.
There is no such pressure in gasoline engines - such a high compression ratio is not needed to burn gasoline. Fuel systems gasoline engines differ in type. There is a distributed injection system (injector), a single-point injection system (mono injection) and a carburetor. Carburetor engines have been discontinued lately and are living out their last days.
Fuel system parts
Regardless of the type of engine, any fuel system comprises fuel pump, fuel pipes and directly the device that supplies fuel to the intake manifold. Such a device is almost always a nozzle, in carburetor engines this role is played by the carburetor.
V modern engines use sensors that affect quality combustible mixture and fuel consumption. The injector and mono injection include an idle speed regulator and a position sensor throttle... An air flow sensor is found in injectors and modern diesel systems. In recent years, an oxygen sensor (lambda probe) has been installed on almost all types of engines.
The device and principle of operation of the oxygen sensor
The oxygen sensor (lambda probe) is located in the vehicle's exhaust system. Depending on the complexity of the design, one or two sensors can be installed, there are also more. If there is only one lambda probe, then it is located on the exhaust manifold.
A lambda probe is a ceramic element in a metal case, which is energized through wires. Ceramic, depending on the qualitative composition of the gases in the exhaust system, sends a signal to the control unit. The fuel consumption control is adjusted according to the sensor readings.
Why the oxygen sensor can fail
The most commonplace, because of which the lambda probe can fail, is mechanical damage. Let's say the car has been in an accident. Often in our Russian conditions the quality of the fuel is to blame. It is not a secret for anyone that gasoline is often "boiled" at gas stations in Russia.
Poor engine condition affects sensor performance. Faulty piston group throws out engine oil v exhaust system, thereby clogging the ceramics at the "lambda".
An incorrectly adjusted ignition leads to overheating of the sensor. Due to the same ignition, pops may appear in the muffler. Strong pops destroy the lambda probe.
Disables the antifreeze oxygen sensor and brake fluid that fall on the ceramic insulator. This can be due to the leakage of fluids in brake system and the cooling system.
The main symptoms of lambda probe malfunctions
It is possible to understand whether the oxygen sensor is working properly or not by some characteristic signs. Although the cause of the problem may be different, professional diagnostics are needed to accurately identify the defect.
A defective oxygen sensor can be if:
- - the car moves with jerks on the road,
- - increased fuel consumption,
- - the car is "stupid", does not drive well and picks up speed,
- - the motor runs unstable at idle,
- - immediately after stopping, a characteristic crackle is noticeable in the area where the "lambda" is located,
- - during an external examination of the sensor, it turns out that it has heated up to a red-hot state (reddened).
If the sensor has broken wires, then there is no doubt that it will not work in this state. In the presence of external damage, it is possible to doubt the operability of the lambda probe.
Yet control lamp The Chek Engine in the passenger compartment signals any malfunctions in the engine's electrical system, but it is possible to pinpoint the malfunction only with the help of computer diagnostics.
Replacing the oxygen sensor
Replacing a lambda probe on a car is very easy, especially if the sensor is located on the exhaust manifold (it is more convenient to get to it). It is better to change it on a well-heated engine, since cold metal is compressed, and the sensor often "sticks" to the manifold.
To replace you need:
- - turn off the engine and turn off the ignition,
- - disconnect the wires at the connector,
- - use a wrench (sometimes a socket wrench is required) to unscrew the faulty sensor,
- - screw the new sensor into place as far as it will go, but without any extra effort,
- - connect the wires at the connector.
That's it, pretty basic. Now there will be no problems with the new sensor.
