It happens at the worst time - stuck in traffic or a long road trip - when you see that check engine light flick on. Here's why it may keep returning.

If your vehicle is throwing a check engine light, but you don't have a diagnostic scanner handy, here are three tricks to try before seeing a mechanic.

The check-engine light is a signal that the onboard diagnostics system (or OBD II) has detected a malfunction in the vehicle's emissions, ignition or fuel systems.

What Is the First Thing to Check When the Check Engine Light Comes On? Start by checking the gas cap first, since that is easy to fix. Beyond that, it’s not a good idea to try and guess what the cause ...

What Your Check Engine Light Means When your check engine light turns on, one or more onboard diagnostic trouble codes are stored in the car’s computer.

Consumer Reports explains what the check engine light means and what to do when you see it: how to tell if your car has a loose gas cap—or a serious engine problem.

Does a check-engine light really mean something is wrong with your engine? What you should do if yours comes on.

Your car's check engine light is a car's way of telling you something is wrong, so it should never be ignored.

While your check engine light is obviously meant for engine issues, it can often give you clues to problems in other parts of the car as well.

A check-engine light could be a gentle reminder or a sign of something catastrophic. We explain what a malfunction indicator light is and what you can do about it.