Why Does the Oxygen Sensor Keep Failing
1 Answers
Reasons for oxygen sensor failure are as follows: 1. Ceramic fracture of the oxygen sensor. The ceramic in oxygen sensors is hard and brittle, and strong impacts or airflow can cause it to crack and fail. Therefore, special care must be taken during handling, and timely replacement is necessary if issues are detected. 2. Burnout of the heater resistance wire. For heated oxygen sensors, if the heater resistance wire burns out, it becomes difficult for the sensor to reach its normal operating temperature, rendering it ineffective. 3. Oxygen sensor poisoning. Oxygen sensor poisoning is a common and hard-to-prevent issue, especially with frequent use of leaded gasoline in vehicles. Even new oxygen sensors may only last a few thousand kilometers. In cases of mild lead poisoning, running a tank of unleaded gasoline can help remove lead deposits from the sensor's surface and restore normal operation. However, often due to excessively high exhaust temperatures, the lead penetrates deeper, hindering oxygen ion diffusion and causing the sensor to fail, necessitating replacement. 4. Carbon buildup. Poor engine combustion can lead to carbon deposits forming on the oxygen sensor's surface, or oil and dust entering the sensor, blocking external air from reaching its interior. This results in incorrect signal output, preventing the ECU from accurately adjusting the air-fuel ratio. Carbon buildup primarily manifests as increased fuel consumption and significantly higher emission levels. If the deposits are cleaned, normal operation can be restored.
