check engine light on 2003 Hyundai Elantra

daughter told me yesterday which was wed that the check engine light came on tues and stays on any ideas of what the problem maybe gas cap is on rite and tight any1 have a 03 elantra that has had this problem?

Asked by for the 2003 Hyundai Elantra
As Roy said, there are many codes a scan tool is required to retrieve codes stored in the computer in your car. Hyundai as a car manufacturer put a lot of free technical information and workshop manuals on line for Hyundai owners. Check out lots of great information.
thanks alot il check it out
1 more answer , 1 more comment
there are over 1200 codes and guessing is not an option. go to a shop and have a free code pull then we can lead to the area of failure.

thanks doin that today