How to Solve the Exhaust Monitoring System Warning Light Issue?
2 Answers
If the exhaust monitoring system warning light turns off after starting the engine, or lights up or flashes while driving, it may indicate unstable operation or excessive exhaust emissions in the emission control system. Other possible causes are as follows: 1. Incorrect fuel: Poor fuel quality, try refueling at a different gas station. If the issue persists, visit a 4S shop to clear the fault light using diagnostic tools. 2. Dirty throttle or air filter: In most cases, the throttle is dirty—cleaning it should resolve the issue. Alternatively, replacing the filter can also achieve the desired solution.
That day when I was driving on the highway, the exhaust gas warning light suddenly came on, which made me quite nervous. I immediately pulled over at a service area. I usually enjoy tinkering with cars, so I connected a portable diagnostic tool to the OBD port and found a fault code indicating an abnormal oxygen sensor. I removed the sensor myself and saw carbon buildup, so I sprayed it with a specialized cleaner and reinstalled it—the light went off. However, if cleaning doesn’t work, it means the sensor is aging and needs replacement. You should also check for exhaust pipe leaks or a damaged fuel cap seal. During the time the light is on, fuel consumption can increase by 20%, so don’t try to save money—address the issue promptly. I recommend keeping some basic tools on hand. When the light comes on, diagnose it first before deciding whether to DIY or visit a repair shop to avoid turning a minor issue into a costly and time-consuming major repair.
