You probably know that in your car installed oxygen sensor (or even two!) ... But why is it needed and how does it work? Stefan Verkhoef (Stefan Verhoef), Denso Manager for Product (Oxygen Sensors), is responsible for frequently asked questions.
B: What kind of work does the oxygen sensor in the car perform?
O: Oxygen sensors (also called lambda probes) help control the fuel consumption of your car, which helps to reduce the volume of harmful emissions. The sensor continuously measures the volume of unburned oxygen in the exhaust gases and transmits this data to the electronic control unit (ECU). Based on these data, the ECU regulates the ratio of fuel and air in the fuel-air mixture entering the engine, which helps the catalytic neutralizer (catalyst) to work more efficiently and reduce the amount of harmful particles in exhaust gases.
B: Where is the oxygen sensor?
O: Everyone new car And most cars released after 1980 are equipped with an oxygen sensor. Typically, the sensor is installed in the exhaust pipe in front of the catalytic neutralizer. The exact location of the oxygen sensor depends on the type of engine (V-shaped or inline cylinder position), as well as from the brand and car model. In order to determine where the oxygen sensor is located in your car, refer to the instruction manual.
Q: Why does the composition of the fuel and air mixture need to constantly adjust?
O: The "air - fuel" ratio is extremely important because it affects the efficiency of the catalytic neutralizer, which reduces the content of carbon oxide (CO), unburned hydrocarbons (CH) and nitrogen oxide (NOX) in exhaust gases. For its efficient operation, it is necessary to have a certain amount of oxygen in exhaust gases. The oxygen sensor helps the ECU to determine the exact ratio of "air - fuel" in the mixture entering the engine, transmitting a rapid voltage signal to the computer, which changes in accordance with the oxygen content in the mixture: too high (poor mixture) or too low (rich mixture). The computer reacts to the signal and changes the composition of the fuel-air mixture coming into the engine. When the mixture is too rich, fuel injection decreases. When the mixture is too poor - increases. The optimal "air - fuel" ratio provides full combustion of fuel and uses almost all the oxygen from the air. The remaining oxygen enters into a chemical reaction with toxic gases, as a result of which harmless gases are already out of the neutralizer.
Q: Why are two oxygen sensors installed on some cars?
O: Many modern cars additionally besides the oxygen sensor located in front of the catalyst, are equipped with a second sensor installed after it. The first sensor is the main and helps electronic block Control regulate the composition of the fuel and air mixture. The second sensor mounted after the catalyst controls the efficiency of the catalyst, measuring the oxygen content in exhaust gases at the output. If all oxygen is absorbed chemical reactionoriginating between oxygen and harmful substances, the sensor displays a high voltage signal. This means that the catalyst is working normally. With the wear of the catalytic neutralizer, a number of harmful gases and oxygen ceases to participate in the reaction and comes out of it unchanged, which is reflected in the voltage signal. When the signals become the same, it will indicate the failure of the catalyst.
Q: What are the sensors?
ABOUT: There are three main types of lambda sensors: zirconium sensors, air-fuel ratio sensors and titanium sensors. All of them perform the same functions, but use various methods Definitions of the "Air - Fuel" ratio and different outgoing signals to transmit measurement results.
The most common technology based on use zirconia and oxide sensors (both cylindrical and flat types). These sensors can only determine the relative value of the coefficient: above or below the "fuel-air" ratio of the lambda 1.00 coefficient (perfect stoichiometric ratio). In response, the motor ECU gradually changes the amount of fuel injected until the sensor starts showing that the ratio has changed to the opposite. From this point on, the ECU again begins to adjust the fuel supply in another direction. This method provides slow and incessant "swimming" around the lambda 1.00 coefficient, without allowing to maintain the exact coefficient of 1.00. As a result, in changing conditions, such as sharp acceleration or braking, in systems with a zirconium-oxide sensor, an insufficient or excess amount of fuel is supplied, which leads to a decrease in the efficiency of the catalytic neutralizer.
Sensor ratio "Air - fuel" Shows the exact ratio of fuel and air in the mixture. This means that the engine's computer accurately knows how much this ratio differs from the lambda 1.00 coefficient and, accordingly, how much it is necessary to correct the supply of fuel, which allows the ECU to change the amount of fuel injected and receive the lambda 1.00 coefficient almost instantly.
The "Air - Fuel" ratio sensors (cylindrical and flat) were first developed by DENSO in order to ensure the compliance of cars with strict emission toxic standards. These sensors are more sensitive and effective compared to zirconium-oxide sensors. The "air - fuel" ratio sensors transmire a linear electronic signal about the exact ratio of air and fuel in the mixture. Based on the value of the resulting signal, the ECU analyzes the deviation of the "air - fuel" ratio from stoichiometric (i.e. lambda 1) and adjusts the fuel injection. This allows the ECU to accurately correct the amount of injected fuel, instantly reaching the stoichiometric ratio of air and fuel in the mixture and supporting it. Systems that use the "air - fuel" ratio sensors minimize the possibility of filing insufficient or excess number Fuel, which leads to a decrease in the number of harmful emissions into the atmosphere, a decrease in fuel consumption, better car handling.
Titanium sensors Largely similar to zirconium-oxide sensors, but atmospheric air is not required to the titanium sensors. Thus, titanium sensors are optimal decision For cars that need to cross a deep ferrod, such as all-wheel drive SUVs, as titanium sensors are capable of working when immersed in water. Another difference of titanium sensors from others is the signal transmitted by them, which depends on the electrical resistance of the titanium element, and not from the voltage or current of the current. Taking into account these features, titanium sensors can be replaced only with similar and other types of lambda probes cannot be used.
Q: What is the difference between special and universal sensors?
O: These sensors have different methods Installations. Special sensors already have a pin connector included and ready to install. Universal sensors may not complete the connector, so you need to use the old sensor connector.
B: What happens if the oxygen sensor fails?
O: In case of failure of the oxygen sensor, the ECU will not receive a signal about the ratio of fuel and air in the mixture, so it will set the amount of fuel supply arbitrarily. This can lead to less efficient fuel use and, as a result, an increase in its consumption. It may also cause a reduction in the efficiency of the catalyst and increasing emission toxicity.
B: How often should I change the oxygen sensor?
O: DENSO recommends replacing the sensor according to the instructions of the automaker. Nevertheless, the effectiveness of the oxygen sensor operations should be checked with each car maintenance. For engines S. for a long time operation or in the presence of signs increased flow Oils intervals between the sensor replacements should be reduced.
Assortment of oxygen sensors
412 catalog numbers Covered 5394 applications, which corresponds to 68% of the European fleet.
Oxygen heated sensors and without (switchable type), air-fuel ratio sensors (linear type), depleted mixture sensors and titanium sensors; Two types: universal and special.
Adjustable sensors (installed in front of the catalyst) and diagnostic (installed after the catalyst).
Laser welding and multi-step control guarantee the exact compliance of all characteristics with the specifications of the original equipment, which makes it possible to ensure efficiency and reliability during long-term operation.
Denso solved the problem of fuel quality!
Do you know that poor-quality or contaminated fuel can reduce the service life and worsen the efficiency of the oxygen sensor? Fuel can be contaminated by additives for motor oils, Additives for gasoline, sealant on engine parts and oil sediments after desulfurization. When heated over 700 ° C, contaminated fuel highlights a pair of pair sensor. They affect the operation of the sensor, forming deposits or destroying its electrodes, which is the common cause of the output of the sensor. DENSO offers a solution to this problem: the ceramic element of DENSO sensors is coated with a unique protective layer of aluminum oxide, which protects the sensor from poor-quality fuel, extending its service life and maintaining its performance at the required level.
Additional Information
For more information on the assortment of DENSO oxygen sensors can be found in the Oxygen Sensors section, in the TecDoc system or the DENSO representative.
The fact that Lambda probe is and for what it is needed, unfortunately, not all car owners know. Lambda Probe is an oxygen sensor that allows electronic system Control and balancing the correct ratio of air and gasoline in combustion chambers. It is able to fix the structure in a timely manner. fuel mixes And warn the destabilization of the engine's workflow.
This fairly fragile device is in a very aggressive environment, so its work must be constantly monitored, since when it is damaged, it is impossible to further use the car. Periodic check of lambda probe will be the guarantor stable work Auto vehicle.
Probe Lambda Probe Probe
The main task of lambda probe is the definition of a chemical service exhaust gases and the level of content of oxygen molecules in them. This indicator should vary in range from 0.1 to 0.3 percent. The uncontrolled excess of this normative value can lead to unpleasant consequences.
With a standard assembly of a car, lambda probe is mounted in the exhaust manifold in the connection area of \u200b\u200bthe pipes, however, sometimes there are other variations in its installation. In principle, the location does not affect the working performance of this instrument.
Today you can meet several variations of lambda probe: with two-channel layout and broadband type. The first appearance is most often found on old cars released in the 80s, as well as on new economy-class models. Sensor broadband type is inherent modern car Middle and highest class. Such a sensor is capable not only to accurately determine the deviation from the norm of a certain element, but also to balance the correct ratio.
Due to the diligent work of such sensors, the working resource of the car is significantly increased, the fuel consumption is reduced and the stability of the holding of non-stroke revolutions increases.
From the point of view of the electrical side, it is worth noting that the oxygen sensor is not capable of creating a homogeneous signal, since this prevents its location in the collector zone, because in the process of reaching the exhaust gases of the device there may be a certain number of working cycles. Thus, it can be said that Lambda probe responds more to the destabilization of the engine operation, which he actually subsequently and notifies the central unit and takes appropriate measures.
Basic signs of lambda probe malfunction
The main sign of the lambda probation malfunction is the change in the engine operation, since after its breakdowns, the quality of the fuel mixture into the combustion chamber is significantly deteriorated. The fuel mixture is essentially uncontrolled, which is unacceptable.
The reason for the exit from the working state of the lambda probation may be the following:
- depressurization of the case;
- penetration of external air and exhaust gases;
- overheating of the sensor due to poor painting of the engine or improper operation of the ignition system;
- obsolescence;
- incorrect or intermittent power supply, which leads to the main control unit;
- mechanical damage due to the incorrect operation of the car.
In all those above cases, except for the latter, the failure occurs gradually. Therefore, those car owners who do not know how to check the lambda probe and where it is generally located, most likely, will not immediately notice a malfunction. However, for experienced drivers, determine the reason for changing the engine work will not be difficult.
A gradual failure of the lambda probation can be divided into several stages. At the initial stage, the sensor ceases to function normally, that is, in certain working hours of the motor, the device ceases to generate a signal, which subsequently destabilizes the magnitude of the idle speed.
In other words, they begin to fluctuate in a fairly extended range, which ultimately leads to the loss of the quality of the fuel mixture. At the same time, the car begins to be dereliciously twitch, you can also hear the uncharacteristic work of the cotton engine and necessarily on the instrument panel lights up the light bulb. All of these abnormal phenomena will signal the car owner on improper work of lambda probe.
At the second stage, the sensor stops working on a non-heated engine at all, while the car will be all sorts of ways to signal the driver about the problem. In particular, there will be a tangible decline of power, slow-down response when exposed to the accelerator pedal and all the same cottons from under the hood, as well as unjustified car jerking. However, the most significant and extremely dangerous signal of the lambda probation failure is the engine overheating.
In case of full ignoring of all previous signals indicating the deterioration in the state of the lambda probe, its breakdown is inevitable, which will cause a large number of problems. First of all, the possibility of natural movement will also suffer, fuel consumption will also significantly increase and an unpleasant sharp smell will appear with a pronounced shade of toxicity from exhaust pipe. In modern automated cars, in the event of a breakdown of an oxygen sensor, an emergency lock may be activated, as a result of which the subsequent movement of the car becomes impossible. In such cases, only an emergency call for the tow truck can help.
However, the worst version of the development of events is to depressurize the sensor, since in this case the movement of the car becomes impossible due to the high probability of the motor breakage and the subsequent expensive repair. During the depressurization of the exhaust gases, instead of accessing through the exhaust pipe, fall into the intake canal of atmospheric reference air. During braking, the lambda engine, the probe begins to fix the overabundance of oxygen molecules and urgently gives a large number of negative signals than completely displays the injection control system.
The main sign of the depressurization of the sensor is the loss of power, it is especially felt during the speed movement, a characteristic tapping from under the hood during a movement, which is accompanied by unpleasant jerks and nasty smellwhich is thrown out of the exhaust. Also about depressurization is evidenced by a visible sediment of planting formations on the case exhaust valves And in the field of candles.
How to determine the malfunction of the lambda probe tells on the video:
Electronic check of lambda probe
You can learn about the status of the lambda probe by checking it on professional equipment. This uses an electronic oscilloscope. Some specialists determine the performance of the oxygen sensor using a multimeter, however, it is capable only to state or refute the fact of its breakage.
The device is checked during the full operation of the engine, since the sensor cannot fully pass the picture of its performance. In the case of even a minor disheaval from the norm, the lambda probe is recommended to replace.
Replacing lambda probe
In most cases, such a detail, as a lambda probe is not subject to repair, as evidenced by the statements about the impossibility of the work of repair from many car manufacturers. However, the overestimated cost of such a node official dealers Breaks off all the hunt for his acquisition. The optimal output from the current situation can be a universal sensor, which is much cheaper than the native analogue and is suitable for almost everyone car Markam. Also, as an alternative, you can buy a used sensor in use, but with a duration warranty period Or a fully final collector with a lambda probe installed in it.
However, there are cases when lambda probe operates with a certain error due to severe pollution as a result of sedimentation on it products of combustion. In order to make sure that this is true, the sensor must be checked from specialists. After checking the lambda probe took place and confirmed the fact of its complete performance, it must be removed, clean and install it.
In order to remove the oxygen level sensor, it is necessary to warm its surface to 50 degrees. After removal, the protective cap is removed from it and only after that you can proceed to clean. It is recommended to use orthophosphoric acid as a highly efficient cleaning agent, which can easily copes even with the most resistant combustible sediments. At the end of the soching procedure, the lambda probe is rinsed in clean water, carefully dried and installed in place. At the same time, do not forget about the lubricant of the thread with a special sealant, which is to provide complete tightness.
Very complicated, so it needs to continuously support the performance and timely preventive work. Therefore, in the event of suspicion of malfunction of the lambda probe, it is necessary to immediately diagnose its performance and in case of confirmation of the fact of failure, replace the lambda probe. Thus, all the most important functions of the vehicle will be preserved at the same level, which will become a guarantor of the lack of further engine problems and other important elements car.
Lambda Probe is a special oxygen sensor or lambda-controller allows you to monitor and measure the quantitative presence of residual oxygen in car exhaust gases.
Main Direction this device - Tracking and transmitting an electronic data management system for fuel combustion and quality by fuel injection. It is due to this that the optimal operating conditions of the exhaust catalyst are ensured.
Prerequisites for the use of catalysts have become rigid ecological standards for road exhaust, since the task of these devices in reducing carbon dioxide. To fully function, uniform combustion in the cylinders burned a strictly defined amount of air with a minimum percentage of deviation.
Such accurate adjustment of the combustible fuel is provided by the power supply system with an adjustable injection electronics. The lambda probe is an oxygen sensor that takes the controller function in the graduation path.
Lambda Probe Installation Place
For maximum productive measurement of indicators of air residue in a burnt mixture, the lambda oxygen sensor must be mounted in the exhaust manifold, located near the catalyst.
The reading of information will be carried out through the fuel management unit, which controls the increase or decrease in the intensity of the fuel injection into the cylinders.
IN modern cars There is an additional lambd probe located at the site of the catalyst exit. This is necessary to increase the accuracy of the preparation of the mixture.
Operating principle
Oxygen sensors on the principle of operation function:
- Based on zirconium oxide.
- Based on titanium oxide. In this case, if the composition of the exhaust is changed, the electrical resistance changes
- Broadband. The change in voltage and polarity of the current is associated with it. Its feature in the ability to react not only to deviations in the composition of the working mixture, but also on its numerical value.
The lambda probation is based on the use of a special electroplating element, in which there is a pair of electrodes. For one of them, the wrapping is exhaust with exhaust gases, and for the other characteristic of a clean atmospheric air.
The working mechanism of the lambda sensor probe is started after heating up to 300 or more degrees, at that moment when the conductor becomes a zirconium electrolyte, and the quantitative difference of incoming oxygen from the exhaust pipe and the atmosphere is directed to the appearance of voltage on the electrodes.
When the engine starts and warms, the oxygen sensor does not affect the fuel injection control, and other signaling devices are adjusted (cooling system temperature sensors, throttle position, revolutions and other).
In addition to the heated zirconium, on the basis of titanium dioxide, cold controllers are cold. They are not created to generate electricity, but aimed at changing the air flow resistance, which serves as the main signal card for injection control systems.
The advantage of such a lambda oxygen sensor is that its work begins immediately after starting the engine, but it has not received widespread, since it is made in a complex design and is expensive. There is a lambda probe of this type in bMW models, Nissan, and Jaguar.
Causes of failure
The oxygen sensor can come into malfunction or start incorrectly operating for a number of reasons:
- if there occurred in the supply or control electro chain, the gap;
- there was a closure;
- if when using fuel with additives, clogged occurred. Lead, silicone, sulfur become the most detrimental;
- due to regular thermal overloads associated with ignition problems;
- it happened after off-road trips mechanical damage.
Any sensor has its own service life and the more, the slower its reaction to the change in the composition of the fuel mixture becomes. The age of the sensor can be well seen on motors with direct injection. It should be borne in mind that if the poor state of the oil dialing rings or occurred to the antifreeze cylinders, the lambda sensor will not stand the lambid and will be replaced.
Attention should be paid to the lambda indicators of the oxygen sensor. It is possible to determine that they are due to the content of carbon dioxide in the exhaust, which increases dramatically from a value of 0.1-0.3% to 3%, and often 7%. If it is found that the oxygen sensor does not work, it is difficult to reduce its value without repair or replacement.
Similar difficulties may also occur in models with two umbrellas, if at least one of them came into a malfunction, it will be necessary to work on a serious change in electronics settings.
Symptoms of the lambda probe output
It is possible to determine the malfunction of the oxygen sensor by the following features:
- the faulty sensor must be immediately changed, otherwise fraught with the failure of the catalyst;
- worsened overclocking dynamics;
- discovered intermitted idling;
- there are jumps of fuel consumption;
- the toxicity of the exhaust is growing, the parameters of which it is impossible to determine without special equipment.
To lambda probe unexpectedly did not become unexpected, it must be changed regularly, non-heated sensors approximately every 50-80 thousand kilometers; Heated after 100 thousand and planar every 160 thousand km. But, in a hurry to throw out the old lambda is not needed. To do this, check the lambda probe on its real state.
It is recommended that checking the lambda of the sensor and the system regulating the fuel mixture every 30 thousand km. It will not be protected from breakage due to mechanical damage or clogging, but will prevent breakdown due to wear.
Timely replacement of the lambda probe is:
- saving up to 15% fuel;
- decline to a minimum of exhaust toxicity;
- the ability to extend the resources of the catalyst;
- ability to improve the dynamic characteristics of the car.
Trouble-shooting
Officially, the technology of repairing lambda probes has not been developed. This means that in the event of a breakdown is not in the contact network, the device should be immediately replaced.
The underground service station has a practice to restore sensors that stopped working due to nagar deposits under a protective cap, through the removal technology of the plaque.
It is carried out through the washing in an orthophosphoric acid of the sensor, which does not have a destroying effect on the electrodes. Such a car wash is not always effective, and if the sensor has not come to the work mechanism after it, it is 100% replaced.
The amount of malicious emissions into the atmosphere is governed by the rigid environmental norms of most countries of the world, including the Russian Federation. To reduce the level of destructive evaporation, catalytic neutralizers were created (or they are also called catalysts). These devices reduce the volume harmful substanceswhich fall into the air together with exhaust gases formed during the operation of the OI.
Undoubtedly, catalysts are the necessary components of the car, however, the effectiveness of their work is due to certain conditions. In the process of the neutralizer, it is necessary to control the composition of the fuel and air mixture, otherwise the useful element will stop performing its functions. In order for the device to work as long as possible, special oxygen sensors can also be used, also known as oxygen sensors, concentration sensors O 2 or lambda probes (LZ).
What is a lambda probe
If we say about what a lambda probe is responsible for, it is easiest to characterize it as a device that determines the level of oxygen, which is contained in the exhaust gases.
The fact is, insufficient air volume in fuel system (λ\u003e 1 is a poor mixture) usually leads to the fact that hydrocarbons and the resulting carbon monoxide will not completely oxidize. If the oxygen is, on the contrary too much in this mixture (λ< 1 - богатая смесь), то оксиды азота не будут разлагаться на кислород и азот. Поэтому наличие ЛЗ в любой системе просто необходимо.
If we consider what lambda probe is in the car, based on its design, the oxygen sensor consists of the following elements:
- Ceramic tip (usually manufactured based on zirconium dioxide), equipped with protective screens, as well as holes for the fence of exhaust gases and atmospheric air. It is these screens that are working elements of the LZ.
- Heat-conducting heating elements that are inside ceramic tips.
- Current collectors of the electrical signal located in the middle part of the oxygen sensors.
All of these components (except sensitive parts of the tips) are closed with a metal body with a thread, due to which the part is fixed on the body of the receiving pipe.
Principle of work lambda probes
Oxygen sensors are equipped with wiring, one end of which is connected to the onboard system of the car, which allows "to request" data from the PLA on the state of the fuel mixture every 2 seconds. With increasing revolutions, the update frequency increases.
In essence, the LAs also function as a galvanic element. After installing in the exhaust manifold, the sensor is heated to 400 degrees under the influence of exhaust flows flowing from the engine. In such a state, the zirconium tip "is activated" and begins to "breathe" with one side of the outer air, and the other - exhaust gases. As soon as one of the electrodes fixes the change in the amount of oxygen, the corresponding signal is transmitted to the machine control system.
The obtained information about the volume of oxygen in the mixture is analyzed by the control system, which allows you to maintain the optimal (stoichiometric) ratio of air and fuel in the car combustion chambers.
Useful! The stoichiometric ratio of oxygen with respect to the fuel should be about 14.7: 1.
To ensure more accurate data adjustment, a second sensor is used, which is placed on the catalyst. However, the number of lambda probes can be more.
How to determine how many oxygen sensors are installed in the car
To find out how many lambda probes are in your car, you can contact the car service where you will be given a printout with data on the diagnosis of PLZ (usually this is a snapshot of the bottom of the machine with dedicated sensors). However, you can save and find them yourself.
First of all, it is necessary to find out in which year a car was made. If you are the owner of the PBX, produced until 2000, most likely, only 1 Lz is installed in it. In more modern machinesReleased after "zero" is usually 2 or 4 sensors.
To determine their number even more accurately, you need to specify the volume of the engine. If it is:
- less than 2 liters, then in the car you will find 2 PHZ (one will be located in the pumproom space, where you will easily notice it, and the second is under the bottom of the car);
- more than 2 liters, then in the car there will be 4 sensors (2 upper, located in the subcontrol space and 2 bottom - under the bottom of the machine).
Finding the upper sensors are quite simple (they are most often changed) for this:
- Open the car hood.
- CENTER open space Under the plastic lid with the name of the brand of the car you find the motor motor.
- Inspect the space around the engine and find massive pipes (exhaust manifold), which one side is adjacent to the motor, and the other go deep into.
- On the graduate manifold, find a small piece of cylindrical shape, the length of which will be about 5-7 centimeters. This will be a lambda probe (or several, in this case one sensor will be located on the right, and the other on the left).
It is worth noting that the information about what the lambda probe needs and where it is located, interests the car owners not because of idle interest. The fact is that according to service books different cars These elements need to be changed after a certain run. Usually, the replacement is subject to LAs that have worked more than 80 thousand kilometers, however, based on the practice, the sensors are able to withstand loads twice as much if you adhere to several recommendations.
How to extend the life of the lambda probes and when to change it
Knowing what the lambda probe affects is quite simple to determine the malfunction of this element. For example, if you notice that:
- on the idling or on a small gas, the motor is unstable, or stalls at all;
- fuel consumption increased significantly;
- the dynamic characteristics of the car sharply deteriorated;
- after turning off the engine, a peculiar crackling in the catalyst region appeared, accompanied by unpleasant odor hydrogen sulfide (or as they say in the commoner of "fucked eggs");
that, most likely, it's time to change the LZ and extend the "life" of this element will not work. However, if all systems work properly, it is possible to increase the life of the sensor if:
- Use only high-quality gasoline recommended for your car.
- Select proven fluids with additives accompanied by certificates of conformity.
- Never use sealants to fix sensors (especially for silicone compounds).
- Do not run the engine repeatedly for a short period of time.
- When checking the performance of cylinders, do not disconnect the spark plugs.
- Do not overheat the exhaust system of the machine (oxygen sensors are able to withstand only up to 950 degrees).
- Do not use chemically active compositions to process sensor tips.
- Watch that the location of the sensor and the pipe remains sealed.
By adhering to these tips, you will be able to exploit the LZ longer on your car.
In custody
You should not neglect such a seemingly simple in terms of design by an element as a lambda probe, as it plays the last role in the functioning of the main machine systems. The cost of a new LZ is about 1,500 - 2,000 rubles, so you can save on it if you exploit the car, given the recommendations of specialists and to diagnose in a timely manner.
Lambda probe (it is an oxygen sensor or oxygen concentration sensor) is a device that determines how much oxygen is contained in the exhaust gases. Learn more about how the lambda probe needs and what is needed, read in our current article.
It is known that the car of the car can work as efficiently as possible only in the case of the correct amount of fuel and air in the fuel and air mixture in each operating mode. This also depends on fuel consumption and effect on the environment. It is for these purposes that the oxygen sensor is used. What is Lambda probe you now know, it's time to consider the principle of his work.
What is needed by a lambda probe in the car
If the amount of air in the fuel and air mixture is not enough, this leads to the fact that carbon monoxide, as well as hydrocarbons are not oxidized in full. But in the case of the presence of too much air volume in the aforementioned mixture, there is no complete decomposition of nitrogen oxides per oxygen and nitrogen.
Oxygen sensor - This is one of the components of the car output system. On some machines, the lambda sensor probe can be installed in two copies. One of them is located in exhaust system Even before the catalyst (it is also called a catalytic neutralizer), and the other after it. The use of two oxygen sensors makes it possible to maximally effectively follow the amount of air in the exhaust gases, due to which the neutralizer functions as efficiently as possible.
Now used two types of oxygen concentration sensors:
- two-point lambda probe;
- broadband oxygen sensor.
Features of the two-point oxygen sensor
The use of two-point lambda probe can be carried out both before the catalyst and after it. This sensor defines an excess air indicator, for which it uses data on how much oxygen is contained in the exhaust gases.
Dual-point lambda probe - This is a ceramic element, on two sides of which the coating made from zirconium dioxide is applied. For measurements, an electrochemical method is used. One part of the electrode is in contact with the atmosphere, and the other with the exhaust gases.
Why do you need a lambda probe of this type, you already know, but how does it work? The principle of its work is based on determining the amount of oxygen in the atmosphere, as well as exhaust gases. If the amount of oxygen differs, voltage occurs at the ends of the electrode. If the air mixture is too poor, the voltage decreases. Otherwise, the voltage increases.
Broadband lambda probe - what is it and how it works
Broadband oxygen sensor - This is the same lambda probe, which is used in modern cars. It performs the functions of the catalyst sensor located on the "entrance". In the oxygen sensor of this type, the determination of the lambda indicator occurs with the use of the input current force.
This lambda probe differs from the sensor mentioned above in the fact that it includes pumping and two-point ceramic elements. Downloading is a process during which oxygen flows from exhaust gases through the corresponding element under the influence of a given current force.
Broadband lambda probe operates on the basis of the principle of maintaining a voltage of 450 mV, which is present between the electrodes of the 2-point ceramic element. For this, the power current is adjusted.
If the amount of oxygen in the exhaust gases falls, which is a sign of too rich fuel-air mixture, voltage increases between the electrodes. After that, the corresponding signal is sent to the engine ECU. Then the formation of the necessary current strength on the pumping element occurs.
The current is necessary for downloading to the measuring gap, which leads to the normalization of the voltage. The current is a measure of oxygen in exhaust gases. Analysis of this indicator occurs in the ECU, after which the appropriate effect on the elements of the fuel injection system is performed.
If the mixture of air and fuel is too poor, the broadband lambda probe works in the same way. It differs in B. this case Just in the fact that as a result of the effect of current, oxygen rolls out from the measuring gap.
To ensure the proper functioning of the oxygen sensor, a temperature of 300 ° C is required. For this, the lambda probe is equipped with a special heater. Now you know what a lambda probe is what the oxygen sensor needs and how it works.
