Why does the CEL come on?

One common issue that triggers the CEL (Check Engine Light) is when the spark plugs are not operating properly. The spark plugs play a crucial role in igniting the air-fuel mixture within the engine cylinders, and any malfunction can lead to inefficient combustion.

When the spark plugs are faulty, your vehicle may experience misfiring, a condition where the engine cylinders do not fire correctly or at all. This can result in reduced power, poor fuel economy, and, more importantly, the potential to damage your catalytic converter rapidly.

Misfiring engines also emit higher levels of pollutants into the atmosphere, posing a threat to both the environment and your vehicle's emissions system. The CEL is designed to alert drivers to such issues, ensuring timely diagnosis and repair.

Another surprising cause of the CEL illuminating is transmission issues. Although the transmission system is primarily responsible for transferring power from the engine to the wheels, faults within this system can also trigger the engine light.

Transmission problems, such as worn-out clutches, faulty sensors, or low fluid levels, can affect the overall operation of the vehicle, including the engine. As a result, the CEL may illuminate as a warning sign, urging drivers to have their transmission inspected and repaired promptly.