The CEL (check engine light) is activated when an engine code is triggered. Often times this is temporary and needs to be reset in order to watch for other codes. There is an easy way to do this.

1. Open the hood. Behind the battery and next to the PCM you will see a black relay box.
2. Open this box by releasing the two plastic tabs.
3. There should be black relay cubes and some assorted fuses in the box. Among the fuses, there is only one rated 20 A. Pull it out and wait about 30-45 sec before replacing it.
4. With the fuse replaced and everything sealed back up, start the engine. The car should sputter and die while the computer re-learns everything.
5. Start the car again. The CEL should be off if this procedure was followed correctly. If it is still on, the problem that tripped the light in the first place is recurring.

Keep in mind that the computer will reset itself so any recording of why the light went on in the first place will be deleted. It is not recommended to reset the computer each time the CEL comes on without taking care of the original problem.