If the check engine light is on, I would go to a auto parts store (ie. Advance) and have them scan the car for the codes. Write them down, post them back to us and we can really go from there.

Otherwise, it could be any number of things, vacuum leak, MAF, MAP, etc... BUT if you get the codes, we would know why the light is on, and be able to help you narrow it down alot easier.