Well When I would go to a stop sign, it would die down then eventually just die. If I would stomp on it then let off it would just die also. So I cleaned the IAC and it did the trick for about 10 minutes. Came back home stopped and it died again, this was about a month ago. Haven't drove it much since. Yesterday I cleaned the IAC again, sprayed some electrical cleaning spray on it and cleand out the throttle body where the IAC goes in. I noticed the IAC was pretty loose when I touched it with a cotton swab to clean it with alcohol. Could that be the problem? It is running pretty good right now since I cleaned it yesterday, but once yesterday when I revved it pretty hard it died again, but hasn't died yet at a stop sign. I can definitely tell it's not idling as well as it SHOULD. While it is working now, coming to a stop sign, the rpms drop very very low and I see my lights dim then it comes back up.

 

Try resetting the PCM. (just disconnect the battery, and turn on the headlights. turn off headlights, reconnect battery.) Jump in the truck, turn the key to "On", but, don't start it yet, count to ten, THEN start it. Drive it normally for a while, and see if that doesn't help. If not, replace the IAC.

 

Lights dimming might be because the engine isn't spinning the alternator fast enough, but it couldn't hurt to have the battery and alternator tested for free at an auto part store.

Sounds to me like you have a fuel issue. Rent a fuel pressure tester from an auto parts store and see what the pressure is when your idle dies down. Another easy thing to check would be the vacuum lines going to the intake for cracks, leaks, etc. If its not any of that, as HeyYou said I'd look into replacing the IAC.

 

Have you pulled your TB and cleaned it? If not, start there.
If resetting the PCM doesn't work, go buy a IAC, as HeyYou suggested.
Do yourself a favor and get one from the dealership. The ones from the parts store don't seem to work right on our motors. Good luck.