2001 Ford Escort Check Engine Light

I just bought my car about 3 months ago and about three weeks ago my check engine light came on. I've had the oil changed and everything checked out. I was told to go get a diagnostic check at the Ford dealership to get a correct reading. Right Now I don't have that kind of cash to be spending an hour at the minumum just for them to tell me whats wrong with the readings. I was wondering if there is anything I can do. The car itself runs perfect. Starts up easy, runs smoothly, and sounds good. There's no ticking or thumping and no odd feelings of difference. Can you please direct me in the right direction.