I was at an auto-x on Sunday and after my second run, the check engine light came on for no apparent reason. I reset it by unhooking the battery, and the light did not come on again, but that is the second time a CEL has come on. I called the dealer and they said not to reset the light.

Any words of advice from anyone as to what could be causing it and what to do about it?

 

The best you can do now is wait for the next CEL. Without any other symptoms you need to read the error code to get any idea what could of happened. All you can do now is to check for the simple maintenence stuff to make sure nothing is obviously wrong.

 

I checked oil, water, battery cables and hold down, oil dip stick, and general wiggling of connections on top of the engine. Nothing seemed to be out of order.

 

use the scan tool at autozone to pull the code. Mabey a misfire?

 

Did you check your gas cap?
The best solution is to pull the code..it could be a number of things.

 

I recently got a flashing at startup maintenance required light after I installed a single exhaust. I remember now that it comes on at a certain milage (just over 26000) and had nothing to do with the exhaust. Is this different than a cel?

 

The "Check Engine Light" (aka, "Malfunction Indicator Light") is NOT the same as the "Maintenance Required Light".
Now that you've cleared the light, you will never know what it was unless it comes back.
ps. There is a better way to clear the light than to disconnect the battery (and a lot simpler). Pull the BACK UP fuse for 30 seconds.