What is the check engine light?
A check engine light is the computer or ECU’s way of relating a small problem to you. Usually it is a minor electrical malfunction in one or more of the feedback sensors, actuators, or solenoids. If the vehicle is still running okay, probably not that serious, though it would be a good idea to have it checked out as soon as possible, even if it goes back out after a little driving. Sometimes these codes can tell the technician a good starting point to diagnose your vehicles. Good example of putting the wrong octane in a Millenia S, can sometimes set a knock sensor code. Not tightening the gas cap after refueling on a 626 can set a code. So sometimes you see it can be your fault not the cars. The more you know of the car the less fear you will have when that light pops on.
