Not sure if this is the right but i think it is transmisision related I have a v6 cavy with an automatic when driving my car normal with it in Drive the car will shift from 1st to 2nd and to 3rd fine. Now say i need to pass some one on the highway when the car down shifts to 2nd its fine until it reaches the shift point to shift into 3rd and the CEL comes on and when i turn the car off then start it back up later it doesnt come on. So basicaly the CEL light comes on if the car is shifting from 2nd and the rpms get to the shift point to go into 3rd most of the time if you are at WOT. If any body has had this problem let me know i have only onwed this car for 5 mo. and it runs and drives perfect no unusual engine or transmision noises just that CEL light comes on but the car still runs fine.

You can check which code(s) your ECM gives you, by using a piece of wire or a paper-clip. If you were to look at the ALDL terminal, as if the thicker part (for aligning the connector) were on the top, jump the 2 rightmost terminals in the top row together. Do this with the car off, then, while the 2 terminals are shorted together, turn the key to the "on" position, but do not start. the check engine light will flash. a 12 means the diagnostic port is working properly (1 flash, short pause, 2 flashes) each code (including the 12) will be repeated 3 times, with a longer pause in between. 3 12's followed by a long pause, followed by 3 12's means no codes. I'm sorry if you have tried this already, sometimes 2nd-gens don't give codes so willingly, unless you shut it off while the light is still on and then check it, but in some cases this is very difficult. me I have a 5-speed, so if the light were to come on, I would step on the clutch and shut the car off and test it quick after coming to a stop. If your light stays on until you shut the car off, there's a good chance of being able to check it before you start the car again. of course this only applies to "hard" codes. "soft" or intermittent codes will only be retrievable by the dealer. Hope this helps...