Welcome to JustAnswer, my name is Dan and I'm here to help get your problem resolved. The check engine light can come on for 100+ reasons, if it still runs fine then its probably only emission related such as a leaking fuel cap. If it runs good its nothing you need to worry about breaking down but still something to get checked out. You can have diagnostic codes checked at your local parts store with a scantool for free otherwise you can check them yourself. Once you get the codes you can reply to this answer at any time without any additional fee's. WIth the codes I can tell you common/possible causes, testing/repair instructions, and costs. Here are instructions to check codes yourself. Let me know if you have questions or if there is anything else I can do to help. Thanks.