You’re driving along in your car or truck and suddenly a yellow light illuminates on your dash telling you to check or service your engine. If you’re like most car owners, you have little idea about what that light is trying to tell you or how you should react.

Call it the most misunderstood indicator on your dashboard: The check engine light can mean many different things, from a loose gas cap to a seriously misfiring engine.

“It doesn’t mean you have to pull the car over to the side of the road and call a tow truck,” says Dave Cappert of the National Institute for Automotive Service Excellence, an organization that tests and certifies auto technicians and is based in Virginia. “It does mean you should get the car checked out as soon as possible.”

Ignore that warning and you could end up damaging expensive components. It can also be a sign that your car is getting poor fuel economy and emitting higher levels of pollutants.

250.00 QAR 1 hour