Check Engine lite

What causes the check engine lite to come on and can it be reset without a fancy device?

Sorry, buddy, but that light's not just for decoration. It usually indicates a part failure in your emissions system. I have scanned out of my FSM several pages on self-diagnosing the system. Once you have diagnosed and fixed the problem, you can reset the light by disconnecting the battery overnight.
Look here for diagnostics (http://www.imagestation.com/album/?id=4291851895)

thanks alot man u have helped alot