Rep Power: 682

oh no the SES light worked VERy well, it came on after i went above 60 and then slowed down below it again on every trip i made, but like i said, it never flashed but it threw the code, so i dunno

 
Rep Power: 783

If you lose a coil it starts misfiring, and when it starts misfiring bad enough, it will make the SES light flash.

 
Rep Power: 682

any idea what would have caused the other problem on that car, i never was able to fix it be 4 i got rid of it, i would like to know WTF was wrong with it. lol

 
Rep Power: 767

Hey glad you got your issue fixed. I'll start off saying I am a far cry from a Mechanic, but I do know computers inside and out.. So what I am discussing below is to be taken with a grain of salt, as in... Its could be right on the money, or way off base.

Usually if you can't find anything mechanically wrong with engine parts, I'll bet its usually going to come down to errant sensors and/or bad wires. As the old adage states "garbage in -> garbage out". If you got a bad sensor (especially and O2 sensor) the PCM is gonna be using the wrong tables on fuel/air mixures, thus loosing power, or running rich ect.

I'm not certain on the firmware of our GMs 3800 pre and post electronic throttle. But I'm betting they have some failsafe defaults built in.. I.E if a sensor is throwing out values beyond normal operating range, it flips on the SES light and runs the engine at a failsafe default setting. Which will get you from point A to B, but limping.

And just like computers, each year car while having same electronics and hardware, may have slightly different software versions as the coders keep tweaking it.. So a 3400 series PCM will probably behave differently than a 3800 PCM when a given error occurs.