Does the car oxygen sensor need cleaning? What is the correct cleaning method?

Observe the tip of oxygen sensor and judge the fault;

1, light gray prompt: This is the normal color of oxygen sensor.

2. White tip: It is caused by silicon pollution. At this time, the oxygen sensor must be replaced.

3. Brown tip (pictured): It is caused by lead pollution. If it is serious, the oxygen sensor must also be replaced.

4. Black tip: It is caused by carbon deposition. After the engine carbon deposit fault is eliminated, the carbon deposit on the oxygen sensor can be automatically removed.

1. Lift the car with a jack, make sure the car is in a proper position, and open the hood.

2. Then take out the automobile oxygen sensor.

3. Then soak the oxygen sensor in the solution, take it out after 10- 15 minutes, and rinse it with water.

principle of operation

The working principle of oxygen sensor is similar to that of battery, and the function of zirconia element in sensor is similar to that of electrolyte. Its basic working principle is that under certain conditions (high temperature and platinum catalysis), the potential difference is generated by using the oxygen concentration difference inside and outside the oxide, and the greater the concentration difference, the greater the potential difference.

. The oxygen content in the atmosphere is 2 1%, and the exhaust gas after rich combustion actually contains no oxygen. The exhaust gas produced after lean mixed combustion or the exhaust gas caused by fire contains more oxygen, but it is still much less than the oxygen in the atmosphere.

Under the catalysis of high temperature and platinum, the oxygen attached to the oxygen sensor is exhausted, resulting in a voltage difference. The output voltage of rich mixture is close to 1V, and that of lean mixture is close to 0V.

According to the voltage signal of oxygen sensor, the air-fuel ratio is controlled to adjust the fuel injection pulse width, so the electronic control of oxygen sensor is the key sensor of fuel metering. Only at high temperature (the terminal reaches above 300℃) can the oxygen sensor fully reflect its characteristics and output voltage. At about 800℃, the reaction to the change of mixture is the fastest.

skill

Zirconia oxygen sensor reflects the change of combustible mixture concentration through voltage change, while titanium dioxide oxygen sensor reflects the change of combustible mixture through resistance change. The electronic control system using zirconium dioxide oxygen sensor can't control the actual air-fuel ratio near the theoretical air-fuel ratio when the engine working condition deteriorates, and the titanium dioxide oxygen sensor can also control the actual air-fuel ratio near the theoretical air-fuel ratio when the engine working condition deteriorates.

The fuel injection quantity (fuel injection pulse width) adjusted by the control unit in a short time according to the oxygen sensor signal is called short-term fuel correction, and its value is controlled by the output voltage of the oxygen sensor.

Long-term fuel correction is the value of correcting the operation data structure of the control unit determined by the control unit according to the change of short-term fuel correction coefficient.

Refer to the above content: Baidu Encyclopedia-Automobile Oxygen Sensor