What is the function of the secondary oxygen sensor?
2 Answers
The function of the secondary oxygen sensor is: 1. To detect the oxygen concentration in the exhaust and send feedback signals to the ECU, which then controls the increase or decrease of the fuel injector's fuel injection volume, keeping the air-fuel ratio of the mixture near the theoretical value; 2. To supplement the control of the primary oxygen sensor in case it fails. Precautions for using the secondary oxygen sensor include: 1. The ceramic material of the secondary oxygen sensor is hard and brittle; striking it with hard objects or washing it with strong airflow may cause it to break and fail; 2. If the heater resistance wire burns out, the heated secondary oxygen sensor will become ineffective; 3. Regular inspections are necessary to avoid internal wire breakage in the secondary oxygen sensor.
Having driven for over a decade, I've learned that the secondary oxygen sensor is primarily installed behind the catalytic converter to monitor oxygen levels in the exhaust. Specifically, it helps the engine control unit (ECU) adjust the air-fuel ratio in real-time, ensuring the catalytic converter processes harmful gases more efficiently and reduces pollutant emissions. Without it, the check engine light can easily come on, fuel consumption may increase, and it could accelerate catalytic converter damage, impacting overall performance. During routine maintenance, I often recommend checking the sensor's connections for tightness to avoid faulty readings caused by aging. This is particularly important for environmental protection, helping vehicles meet modern emission standards and prolonging engine life. Modern cars rely heavily on this component to optimize driving experience—never overlook minor issues. Once it fails, repair costs can be substantial, and diagnosing trouble codes becomes more demanding. In short, it's an unsung hero that keeps the engine running cleaner and more efficiently.
