What are the impacts of a faulty oxygen sensor?

[MarianaLee]

Damage to the oxygen sensor can lead to the following consequences: 1. When the front oxygen sensor fails, the ECU cannot obtain information about the oxygen concentration in the exhaust pipe, thus unable to provide feedback control on the mixture concentration. The ECU has no way of knowing the amount of fuel injection and air intake, leading to increased engine fuel consumption and exhaust pollution. The engine may exhibit unstable idling, misfires, surging, and other fault phenomena. 2. A rear oxygen sensor failure means the operating condition of the three-way catalytic converter cannot be determined. If the three-way catalytic converter malfunctions, the exhaust emissions will exceed standards, which could mildly increase fuel consumption and affect engine performance, or severely impact annual inspections or necessitate the replacement of the three-way catalytic converter. 3. Cars usually have two oxygen sensors, one front and one rear. The front oxygen sensor is typically installed on the exhaust manifold, while the rear oxygen sensor is installed behind the three-way catalytic converter. They play different roles in the exhaust system, so the symptoms of failure will also vary.