I just replaced the IAC ...and reset the CPU and I still have a terrible rough idle...........whats next....????????? My code read ...."left bank too lean." and the other code read "right bank too lean".

I can't stand driving my truck.......It idles like ****!

 

Definitely don't drive too much with lean codes, it can seriously damage your engine. The next things to check would be EGR valve, 02sensors, MAF sensors, because something is causing the PCM to cut the air/fuel ratio and give you a lean code.

 

lean codes dont have a thing to do with iac really. Things to do:

Change your fuel filter, when was the last time?
Vacuum leaks, check everything, esp that boot behind the intake, i think you have one
Can be the pcv, its 4 bucks, just change it
Can be fuel pump, pray it isnt, twice a day.
You have a k&N or other cotton oiled filter? clean your maf.

Thats about all i can think of. My money is on vacuum leak.

Oh and don't drive, lean likes to make things blow up.