1. Oxygen sensor poisoning
Oxygen sensor poisoning is a type of failure that often occurs and is difficult to control, especially for cars that often use leaded gasoline. Even new oxygen sensors can only work for thousands of kilometers. If it is only a slight lead poisoning, then using a box of lead-free gasoline, the lead on the surface of the oxygen sensor can be eliminated and returned to normal operation. However, due to the excessive exhaust gas temperature, lead is intruded into the interior, hindering the diffusion of oxygen ions, and the oxygen sensor is disabled, and then it can only be replaced.
In addition, silicon poisoning in oxygen sensors is also a common occurrence. In general, silica produced by burning silicon compounds contained in gasoline and lubricating oil, and silicone rubber gaskets using improperly emitted silicone gas will cause the oxygen sensor to fail, so use good quality fuel and lubricating oil. . The rubber gasket should be properly selected and installed during repair. Do not apply solvents and anti-blocking agents other than those specified by the manufacturer.
2. Carbon deposit
Because the engine is not burning well, carbon deposits on the surface of the oxygen sensor, or deposits such as oil or dust inside the oxygen sensor will block or block the outside air from entering the oxygen sensor, causing the signal output from the oxygen sensor to be out of alignment, and the ECU cannot be timely. Correct the air-fuel ratio. The accumulation of carbon is mainly caused by an increase in fuel consumption and a significant increase in emission concentration. At this point, if the sediment is removed, normal operation will resume.
3. Oxygen sensor ceramic chipping
Oxygen sensor ceramics are hard and brittle, and they can be broken and failed by hard objects or by blowing with a strong air stream. Therefore, be careful when handling and find problems in time.
4. Heater resistance wire is blown
For a heated oxygen sensor, if the heater wire is ablated, it is difficult to cause the sensor to reach its normal operating temperature and lose its effect.
5. The internal circuit of the oxygen sensor is broken.
6 oxygen sensor appearance color check
Remove the oxygen sensor from the exhaust pipe and check the vent hole on the sensor casing for blockage and damage to the ceramic core. If it is damaged, the oxygen sensor should be replaced.