I have a 06 F150 4.6 w/120,000 miles. Recently I've noticed a rough idle. Don't really notice it on the road. I've changed the fuel filter, cleaned the MAF and throttle body. Changed the plugs around 90,000 miles. Air filter is still good. Recently ran two tanks of fuel with Gunk fuel injector cleaner. About 3 months ago I did the Seafoam in the brake booster vaccum line.

Where do I go from here?

 

dont know if this will help(probably not) at all but i had idle problems on my 90 f150 and i replaced some air bypass valve on top the motor and it fixed the problem completely

 

Clean the iac on the side of the throttle body, (Idle air censor)

 

hook up a scanner and see if it's throwing an OBDII code (could store a code but not trip check eng light), could have to do with your EGR pressure too...

 

I don't believe their is a IAC on the 04+ models.