Causes of Oxygen Sensor Failure?

[KevinDella]

Here are the specific causes of oxygen sensor failure: 1. Ceramic breakage in the oxygen sensor: The zirconia oxygen sensor's ceramic is hard and brittle. During installation or maintenance, avoid striking it with hard tools or washing it with strong airflow, as these actions may cause the ceramic to break. Special attention is required. 2. Heater resistance wire burnout: The heater resistance wire heats the oxygen sensor to allow it to enter the working state early. If the heater resistance wire is burnt out, it becomes difficult for the sensor to reach the normal operating temperature and thus loses its function. 3. Internal wiring disconnection in the oxygen sensor: Many internal wiring issues in the oxygen sensor are caused by poor connections between the wiring harness and terminals. The failure may also result from interference by other electrical systems, mechanical or chemical damage. Sometimes, the wiring may be disconnected or come loose due to maintenance or other reasons.

[ClaytonMarie]

I've been driving for decades and have encountered oxygen sensor issues several times, summarizing some common causes. The main problem is contamination, such as poor engine combustion leaving excessive carbon deposits or oil leaks coating the sensor, directly clogging the sensing element. Circuit aging or vibration can also loosen or short-circuit the wiring harness, easily leading to sensor failure. External factors play a significant role too; using low-quality gasoline or chemical additives accelerates contaminant buildup, causing the sensor to fail quickly. Thermal damage is another major issue – frequent engine starts or numerous stop-start cycles cause the sensor to expand and deform due to high temperatures. The symptoms are obvious: the engine light comes on, fuel consumption spikes by over 20%, and idle becomes unstable. I recommend experienced drivers not overlook these signs – regularly inspect the exhaust system, use high-quality fuel, and avoid modifications that could affect the sensor's position.