Just had a question, my Check Engine light turned on for about a week and then just a couple days ago it went off and hasnt been on since. What could it be?

 

Take it to autozone and ask them to run the codes for you. I believe they do it for free as long as you don't take the computer home. If not a local smog shop may run it for you. Once you get the code look it up and you can get to the bottom of the problem that way. No one knows what it could be with the info you gave cause CEL's have so many different things that could be wrong.