What are the signs of a faulty front oxygen sensor?
2 Answers
When the front oxygen sensor fails, the ECU cannot obtain information about the oxygen concentration in the exhaust pipe, and thus cannot perform feedback control on the mixture concentration. This leads to increased fuel consumption and exhaust pollution, and the engine may exhibit symptoms such as unstable idling, misfiring, and surging. Here is some additional information about the front oxygen sensor: 1. The main function of the front oxygen sensor is feedback. Simply put, it detects the oxygen content in the exhaust gas produced after the combustion of the air-fuel mixture in the cylinders. Generally, a high oxygen content indicates a lean mixture, while a low oxygen content indicates a rich mixture. The front oxygen sensor sends different electrical signals to the ECU based on the oxygen content, allowing the ECU to adjust the mixture accordingly. 2. The exhaust gas produced by the car's combustion must pass through the catalytic converter for purification before being released. The rear oxygen sensor detects the oxygen content in the purified exhaust gas and feeds it back to the ECU. The computer then compares the data from the front oxygen sensor. If the data from the front and rear oxygen sensors are the same, it can be concluded that the catalytic converter has failed.
I've been repairing cars for many years, and the signs before the front oxygen sensor fails are quite obvious. The engine warning light coming on is the most common alert, as it constantly monitors emissions. You'll notice a sudden increase in fuel consumption – I've encountered car owners complaining about spending dozens more yuan per 100 kilometers. The engine also runs unevenly, shaking severely at idle as if it's about to stall, and struggling when accelerating or climbing hills with insufficient power. There's also a foul smell in the exhaust, similar to sulfur or rotten eggs, indicating incomplete fuel combustion. Ignoring it for a long time may damage the catalytic converter, doubling repair costs. I recommend using an OBD scanner to check error codes at the first symptom and fix it promptly to avoid affecting driving safety, which is also crucial for the vehicle's overall health.
