Check Engine Light

2008 Hyundai Tucson. Check Engine light has been on for 3 days. No running problems, gas cap on properly, tires properly inflated, Fluid levels O.K. Whats up?

The drivetrain management system has detected a fault somewhere. So a sanner/code reader has to be plugged into diagnostic connector to retrieve the codes. Some parts stores like AutoZone will do this for free.

Tester

It could be many things, but most cars have a computers that keeps track of problems and stores information about what may be wrong. The first step is to have the computer scanned to see if there are any error codes. Some autopart stores will do this for free; try Autozone or Advanced Auto Parts.

Just because your engine seems to be running fine does not mean something is not working right that could cause more expensive repairs if you don't do something now.  Many times it is nothing more than a loose gas cap, other times you might be destroying your catalytic converter or something else.

It is really foolish to ignore it.