The check engine light is an indicator that there is a problem with the vehicles emission control system. Let’s talk about what it means when the check engine light comes on in your car or truck. 

What is the emission control system?

The emission control system in automobiles is used to help limit the discharge of gasses produced by the engine. These gas can come from the vehicles exhaust, the crankcase or the fuel tank and carburetor. Two main systems are used to control the release of these pollutants. The air injection system, and the exhaust gas recirculation system. These systems contain multiple sensors that relay information to the cars central computer.

When one of the sensors gets a reading that is outside of an acceptable range, the computer sets a code and turns on the check engine light. The problem could be in the engine itself. Or, with the engine management components, the exhaust system, or the fuel tank vapor system.

Is it Ok to drive with the Check Engine light on?

If the light comes on it’s ok to keep driving. It doesn’t mean something bad is about to happen. But, you should get the vehicle in for service when you are able to do so.

If the light comes on and it’s blinking, however, that means there is a severe problem and the vehicle should not be driven very far, and you should get it in for service as soon as possible. Since the check engine light indicates there is a problem with the emissions system, you cannot pass a smog test if the light is on. While most of the time it’s possible to continue to drive the vehicle with the light on, there is a risk that the problem will eventually cause damage to other parts and the repair will become more expensive. For example, a bad oxygen sensor or an engine misfire can cause a rich fuel condition that will overwork and damage an expensive catalytic converter, as well as decreasing fuel mileage. It’s best to get the problem resolved as soon as you are able to do so.