* Loose or faulty gas cap. A loose or faulty gas cap can cause the "check engine" light to come on because it allows fuel vapors to escape from the fuel system. This can cause the engine to run rich and waste fuel, and it can also damage the catalytic converter.
* Oxygen sensor problems. The oxygen sensor monitors the amount of oxygen in the exhaust gas and helps the engine to adjust the air-fuel mixture. If the oxygen sensor is faulty, the engine may run rich or lean, which can cause the "check engine" light to come on.
* Spark plug problems. Spark plugs are responsible for igniting the air-fuel mixture in the engine. If a spark plug is faulty, it can cause the engine to misfire, which can lead to the "check engine" light coming on.
* Catalytic converter problems. The catalytic converter helps to clean up the exhaust gas by converting harmful pollutants into less harmful substances. If the catalytic converter is damaged or faulty, it can cause the "check engine" light to come on.
* EVAP system problems. The EVAP system is responsible for controlling fuel vapors from the fuel tank. If the EVAP system is faulty, it can cause the "check engine" light to come on.
If the engine light comes on, it's important to have the vehicle inspected by a qualified mechanic to identify the cause of the problem and have it repaired as soon as possible.
