[Dan in Pasadena]

Whew, I went to bed at 1:00a.m. and had a busy day. Didn't get back to my thread until now and there have been a lot of responses. First, thanks everyone.

I have a stupid idea, here it is: I noticed that my truck has a plastic top tank separate from the radiator and that some of the coolant has leaked out and dried on top of the tank. It occurs to me that may be the radiator cap pressure spring has gone soft and that this could cause the check engine light? Preposterous, or remotely possible? I agree that rather than guessing I should get it checked. Since Autozone offers to check it I will start there but also I am in agreement with all, especially IM6Y when he writes,

"A capture function is a good thing to have also. It captures data from all of the sensors at the instant you press a button. It's great for finding intermittant problems that won't set a code, but bugs the crap out of you. "Most" OBD2 systems will store all of the sensor data when the code was set also."

So I will look more seriously at buying an OBDII unit that uses my computer. Reason: I have twice had this truck refuse to shift into first gear after a sustained (hours) run at freeway speed towing my jetski trailer with two skis. Took it to the dealer the first two times (still under warranty then) and they reported they couldn't duplicate the problem and the computer had recorded no codes....leaving them not knowing what to do I suppose. After shutting off the truck and restarting the problem has disappeared - buggingthe crap outta me! This needs to be investigated before I need to rebuild the trans or something! I'll post after I get the Autozone reading. Thanks everyone, Dan