From the article you will learn about what an oxygen sensor is. Symptoms of this device will make you think about replacing it. Because the first sign is a significant increase in gas mileage. The reasons for this behavior will be discussed below. And first, it’s worth talking a little about the history of this device, as well as its principles of operation.
The need for an oxygen sensor
And now about why an oxygen sensor is needed in a car. Symptoms of it will be considered later. When burning any fuel, oxygen access is required. Without this gas, the combustion process cannot take place. Therefore, oxygen must necessarily enter the combustion chambers. As you know, a fuel mixture is a combination of gasoline and air. If pure gasoline is poured into the combustion chambers, the engine will simply not work. By how much oxygen remains in the exhaust system, we can say how efficiently the air-fuel mixture burns in the engine cylinders. It is for measuring the amount of oxygen that a lambda probe is needed.
A bit of history
At the end of the 60s, for the first time, auto designers began trying to install these sensors on cars. The very first oxygen sensors were installed on Volvo cars. An oxygen sensor is also called a lambda probe. The fact is that there is a letter “lambda” in the Greek alphabet. And if we turn to the reference books on internal combustion engines, we can see that this letter denotes the coefficient of excess air in the fuel mixture. And this parameter allows you to measure the oxygen sensor (lambda probe).
Principle of operation
The oxygen sensor is installed exclusively on injection vehicles that use electronic engine control units. The signal generated by him is fed to the control unit. This signal is used by the microcontroller in order to make the correct adjustment of the mixture formation. It adjusts the air supply to the combustion chambers. Of course, the quality of the mixture is affected not only by the signal from the oxygen sensor, but also by most other devices that allow you to measure the load on the engine, its speed, as well as the speed of the car, and so on. Often in cars two lambda probes are installed. One is a worker, and the second is for adjustment. They are installed before and after the collector. Please note that the lambda probe that is mounted after the collector has additional forced heating. Before cleaning the oxygen sensor, be sure to read the requirements that are imposed by its manufacturer.
Lambda probe working conditions
It is also worth considering that the most effective functioning of this sensor occurs at temperatures from 300 degrees and above. It is for this purpose that an electric heater is needed. It allows in the mode of cold engine to maintain the normal functioning of the oxygen sensor. The sensor element must be located directly in the exhaust gas stream. So that its electrode, located on the outside, must be washed by the stream. The inner electrode must be located directly in the air. Of course, the oxygen content is different. And between these two electrodes some potential difference begins to form. A maximum of 1 volt voltage may appear at the output. This voltage is supplied to the electronic control unit. That, in turn, analyzes its signal, then, according to the fuel card incorporated in it, increases or decreases the nozzle opening time, changes the air supply to the ramp.
Broadband
There is such a device as a broadband oxygen sensor. Symptoms (UAZ "Patriot" has the same as any other car) of the sensor are that the operating mode of the engine is changing. The difference between a conventional and such a device is quite large. The fact is that they have completely different principles of functioning and sensitive parts. And broadband lambda probes are more informative, and this is true for cases when the engine is operating in non-standard modes. Therefore, the richer the information, the more accurate the settings will be made by the electronic control unit.
How to identify a breakdown
It is worth noting that oxygen sensors affect the functioning of the motor very strongly. If suddenly a lambda probe orders a long life, then the engine will most likely not work. When a lambda probe breaks down, no signal is generated at the output, or it changes in an unpredictable way. Of course, this behavior will greatly complicate your daily life. A sensor can fail literally at any moment. For this reason, certain functions are provided on vehicles that allow you to start the engine and also get to the service station, even if the oxygen sensor is defective.
Emergency firmware
The fact is that when the electronic control unit sees a breakdown of the lambda probe, it does not start working on the firmware that is installed in it by default, but on the emergency one. In this case, mixture formation occurs according to data obtained from other sensors. Only the oxygen sensor is not involved in this process. The driver will notice signs of a malfunction of this device immediately. Unfortunately, the mixture is too poor, since the percentage of gasoline is more than necessary. This ensures that the engine does not stop. But if you increase the air supply, then it is likely that the engine will stall. However, as a warning on most cars, the Check Engine lamp in the dashboard lights up, which signals engine malfunctions. The literal translation of this inscription is "Check the engine." But even without it, you can determine the breakdown of the lambda probe. The fact is that fuel consumption is growing significantly compared to normal mode.
Conclusion
Now you know what an oxygen sensor (lambda probe) is, what its properties and features are. In conclusion, I would like to mention that this element is very demanding on how it is installed. Make sure that there are no gaps between the sensor body and the collector, otherwise this will lead to premature failure of the device. In addition, during operation, the sensor will send incorrect information to the control unit.