3p0x1fx4

My 05 FX4 does the same thing from time to time. We have a few newer 5.4's at work and they all do the same thing too. For me, I've seen more with the rough idle than without. Not sure if it's a common problem or just how the engines are balanced. I plan on replacing my plugs and injectors in a few months but I doubt it's going to fix it...

rickyp

I got in the other station's f150 and it was idling about the same as my but a little worse.

camohr

try cleaning the throttle body..they get real gummed up quickly...i clean mine about every 15-20k along with an injection service

Mod (Ret.)

DON'T! No need to clean or re-oil it so soon. Go to K&N's web site and read their directions (they state when and how to clean it).

rickyp

I took the truck in today and the dealer told me they couldn't get it to idle rough but they did clean the mass ait sinsor becasue the K$N filter let dirt pass by it.

I put the K&N filter on 6-12-09 and has 14,197 miles on it. mostly highway.