My idle is acting up after I installed a 68.5mm Fastman throttle body. It doesn't do it all the time but maybe 50% of the time when I slow down to a stop the idle seems to rev up and down. I unplugged the battery the whole time I was installing it to reset the memory or whatever. I haven't done anything else that would cause this besides the upgraded throttle body. Anyone have a solution? Is it just in "learning mode" still?

I've got a video I made of it you can see by clicking the youtube link below.

http://www.youtube.com/embed/UzDRMP5Vrc8

I just remembered that one of the O-rings on the IAC was a little stretched out and should be replaced. I'm going to replace both O-rings tomorrow and see if it fixes that idle issue.

 

Sounds like it may just be relearning the new air flow.

With the engine cold, disconnect the negative battery cable for 1-2 minutes, reconnect and start engine (DO NOT REV) letting it idle and come up to operating temp. Shut engine off, restart and go for a drive making as many stop & go's as possible, such as stop signs, to help the PCM relearn the part throttle settings. See if that helps.

 

I replaced the IAC valve and TPS sensor and my truck is running awesome!