* Oxygen sensor failure. The oxygen sensor monitors the amount of oxygen in the exhaust gas and helps the engine adjust the fuel mixture accordingly. If the oxygen sensor fails, the engine may run rich or lean, which can cause the service engine soon light to come on.
* Spark plug failure. Spark plugs provide the spark that ignites the fuel in the engine. If a spark plug fails, the engine will misfire, which can cause the service engine soon light to come on.
* Fuel injector failure. Fuel injectors spray fuel into the engine. If a fuel injector fails, the engine will not get the fuel it needs to run properly, which can cause the service engine soon light to come on.
* Catalytic converter failure. The catalytic converter helps to convert harmful pollutants in the exhaust gas into less harmful substances. If the catalytic converter fails, the engine may not be able to pass emissions testing, and the service engine soon light will come on.
If the service engine soon light is on in your 2002 Saturn SL1, it is important to have the vehicle diagnosed and repaired as soon as possible. Driving with the service engine soon light on can damage the engine and other components of the vehicle.
Here are some additional tips for diagnosing and repairing the service engine soon light in a 2002 Saturn SL1:
* Check the owner's manual for information about the service engine soon light.
* Have the vehicle scanned for trouble codes. This will help to identify the specific problem that is causing the service engine soon light to come on.
* Once the problem has been identified, have it repaired as soon as possible.
* Keep up with regular maintenance on your vehicle to help prevent the service engine soon light from coming on. This includes changing the oil, filter, and spark plugs at the recommended intervals.
