my truck won't idle

It's possible the throttle position sensor has gone bad, or one of the oxygen sensors. You may want to have this checked by a dealership. When the engine is cold the onboard computer uses a preprogrammed fuel-air mixture until it kicks down to curb idle. It's possible the problem is as simple as reflashing your ECM to "re-learn" the correct warm fuel air mix. A dealership can do this for you.