What should I do if the oxygen sensor frequently malfunctions?
3 Answers
If the oxygen sensor frequently malfunctions, you should check whether the spark plugs and ignition coil's operating voltage are normal, and inspect whether the three-way catalytic converter is functioning properly or if there is any blockage. If the oxygen sensor fails, the computer of the electronic fuel injection system will not receive information about the oxygen concentration in the exhaust pipe, thus unable to perform feedback control on the air-fuel ratio. This will lead to increased engine fuel consumption and exhaust pollution, as well as engine issues such as unstable idling, misfires, and surging. Oxygen sensor poisoning is a common malfunction, which can be divided into two types: lead poisoning and silicon poisoning. The former often occurs in cars using leaded gasoline, while the latter is caused by silicon dioxide generated from the combustion of silicon compounds present in gasoline and lubricating oil.
I've been repairing cars for twenty years, and oxygen sensors often malfunction mostly due to severe carbon buildup in the exhaust pipe, poor fuel quality, or a clogged air filter. When carbon deposits get thick, the sensor gives false readings, causing the car's fuel consumption to skyrocket and the fault light to come on, making the drive rough. I recommend regularly spraying the sensor with professional cleaner, and if that doesn't work, replace it with a new one—don't skimp and buy off-brand products, or the problem will recur. Also, check that the exhaust system is sealed with no leaks and that the wiring connections are secure. For prevention, develop the habit of using high-quality gasoline and avoid letting the engine idle for long periods, as this can easily lead to carbon buildup. A healthy sensor ensures tailpipe emissions meet standards, is environmentally friendly, and can save a lot on fuel costs when fixed. Most importantly, it protects the engine, making it more durable.
Having driven for 15 years, I find oxygen sensors constantly failing really annoying. My fuel consumption has risen from 8L to 13L, burning money on gas. I use an OBD2 scanner with a mobile app to check error codes, commonly encountering sensor issues like P0420. Buying aftermarket parts and replacing them myself costs about 200 yuan, saving a lot of hassle. I recommend regular highway driving to clear carbon deposits, preventing faults and maintaining proper air-fuel ratio. High-mileage cars are more prone to sensor issues, so keeping simple tools at home helps avoid panic when problems arise and prevents being overcharged at repair shops. Fixing sensors improves power, eliminates foul exhaust, and makes driving much smoother.
