Reasons why check engine light comes on?

The check engine light can illuminate for various reasons, including issues with the engine's emissions system, faulty sensors, or problems with the fuel system. Common triggers include a loose or damaged gas cap, worn-out spark plugs, or catalytic converter malfunctions. Additionally, it may indicate more serious issues like engine misfires or transmission problems. It's advisable to have the vehicle diagnosed with an OBD-II scanner to identify the specific cause.