I have an 02 XLT 5.4 V8
When I start the truck it fires just fine, but the truck idles with rpm's "bouncing" up and down about 200 rpm's or so. This idle eventually smooths out and resumes normal function. I have a small exhaust leak on the manifold if that has anything to do with it. I also have a TB spacer just for the cool whistling noise which i can take off if I need to. I'm going to clean my MAF sensor today and hope that clears it up. Any insight on what I need to do is appreciated.

 

Cleaning the MAF is the first step, then maybe clean the TB. Clean the spacer too. LOL

 

Clean the IAC if your going to pull the throttle body elbow. Takes a good hour to pull it, clean everything and put it back. Clean the egr ports on the throttle body also. Well worth it.

 

Any codes? Sounds like the PCV elbow is leaking intermittantly? Possibly the DPMF sesnsor?

 

No codes, thanks I just checked, but I'm gonna go clean the whole intake right now and we'll see how it turns out