What are the oxygen sensor fault codes?
2 Answers
Oxygen sensor fault codes include: P0134 indicates no signal from the upstream oxygen sensor; P0135 indicates a fault in the heating circuit of the first sensor in the first group; P0141 indicates a fault in the oxygen sensor heater circuit. The oxygen sensor is a sensor that monitors exhaust gases, responsible for measuring the oxygen content in vehicle emissions. After the exhaust is emitted, if the air-fuel mixture is too rich or too lean, it sends a signal to the vehicle's computer to adjust the fuel supply. When the oxygen sensor fails, the exhaust warning light will activate, the engine emissions will become non-compliant, and the vehicle may experience reduced power. It is crucial to repair any oxygen sensor faults promptly.
I remember my old car had oxygen sensor issues several times, with common trouble codes including P0130, P0131, P0135, P0140, etc., which all belong to standard OBD-II system codes. P0130 indicates abnormal sensor circuit, possibly due to short circuit or disconnection in wiring; P0135 is a heater circuit malfunction, especially prone to triggering in cold winter temperatures; P0140 means no activity signal from the sensor, usually indicating complete sensor failure. In terms of symptoms, unstable engine idle, fuel consumption surging by over 20%, and pungent exhaust smell are all clear warning signs. Last time my check engine light came on, it was caused by P0135, and replacing the sensor after inspection solved the problem. It's advisable to regularly scan with diagnostic tools, such as using a Bluetooth OBD scanner connected to a phone to check codes, to avoid prolonged issues leading to catalytic converter damage or exceeding emission limits. Additionally, since the sensor is near the exhaust system, it's prone to carbon buildup; cleaning the connector might provide a temporary fix, but professional repair is recommended.
