The car dies sometimes when idle and sometimes when traviling at

Dirty throttle plate an bore , sticking open EGR valve , IAC - idle air control valve passages dirty or IAC valve is going bad.
Quick Tip Throttle Cleaning EricTheCarGuy
007 Idle Speed Problems Scan Data for Idle

If the EGR valve was stuck open it wouldn't idle at all ! That's the only way an EGR valve could be a problem at idle , EGR valves are not energized by the PCM - engine computer at idle . EGR valves operate at speeds higher , highway speed to deceleration . Getting off free way . You have an IAC valve problem ,idle air control valve . Or possibly a TPS - throttle position sensor Or a vacuum leak (intake manifold ) Or maybe a mass air flow sensor or some other sensor . Don't listen to peoples suggestions , you'll only spend a bunch of money on parts an still have the same problem . Do yourself a favor an take it to a qualified repair shop !

idling problems are usually created by a few things all attributable to the inlet manifold clean the earth behind the injectors. Spray soap and water around the gasket connecting the manifold to the head if it bubbles it leaks fix. Check all hoses are connected to the vacuum points around the throttle body if these are good , There are two points of idling controls at the throttle body electronic throttle positioning sensor located on the butterfly the other below this is the idle speed control sometimes the O-rings die around these and need to be replaced alternatively replace both . Check your fuel control valve , O-rings on this and the injectors create problems on the fuel rail

could be the EGR or the IAC idle air control

Engine stalls cold or RPM fluctuates at idle up and down or dies near idle.

This problem is commonly caused by a dirty automatic idle speed control valve and throttle valve but always run a OBD2 fault code as well as the cleaning procedure. Buy a can of throttle valve cleaner (do not use carburetor spray cleaner!) from NAPA or Carquest (made by CRC chemicals) and spray it into the air intake while the engine is running, use up about 1/2 the can, engine will try to stall hold the speed up, shut it down and let it soak for 30 minutes, restart and blow out the remaining fluid, shut it down and disconnect the negative battery cable for 5 Min's to reset the base idle control. If the above cleaning doesn't cure your issues you need to have the computer controlled automatic idle speed control system diagnosed and repaired by a dealer or electronic engine control repair shop.

when motor cold it will rev up around 2000 then drope down

r u gonna keep replacin parts-or do a scan 1st--not all problems show on a readout-like vacuum leaks or a failin computer--throttle body probly needs cleanin

idl air control (IAC),may be bad,also,check the EGR valve,and all vacuum lines going and coming from the throttle body. yu can test the EGR,just try pushing the diaphram by hand from beneath. if you can move it easily its good,if its hard,or doesnt move,ot needs repaced. also a pcv valve and air filter are good ideas,considering you have replaced 80% of the emission system already.

sounds like you have a egr that is stuck open
remove the egr valve clean it and see if that helps
of not replace it should improve the idling

Hello. I bet your problem is one of these two things. 1: your timing is out. Making it run at such a low idle that it stalls itself out. 2: your truck is running too rich and flooding itself out. Just adjust theb timing a bit and lean the motor out a bit and you should be as good as new! Hope this helps!