* Faulty Oxygen Sensor: The oxygen sensor measures the amount of oxygen in the exhaust and helps the engine control module (ECM) adjust the air-fuel mixture. A faulty oxygen sensor can cause the ECM to make incorrect adjustments, leading to an illuminated check engine light.
* Vacuum Leak: A vacuum leak can cause a lean air-fuel mixture, which can lead to an illuminated check engine light.
* Faulty Spark Plugs: Worn or damaged spark plugs can cause misfires, leading to an illuminated check engine light.
* Faulty Ignition Coil: A faulty ignition coil can prevent the spark plugs from firing properly, causing misfires and an illuminated check engine light.
* Catalytic Converter Issues: A failing catalytic converter can cause the engine to run rich, leading to an illuminated check engine light.
