It could easily be a dirty throttle body or even just a couple of fouled spark plugs - maybe a faulty plug. Have you replaced the plugs? Have you checked that all the high tension wires are firmly in place at the plugs? Isn't she still under warranty?
yeah she's still under warranty, if it wasn't yeah i'd be under that hood real quick pullin plugs n **** but i don't wanna void the warranty and tamper with it so i better do it through ford that way if it turns out to be more then just dirt i won't have to pay for parts. the truck only has 28800km on it
I had the same rough idle in my 98 4.6l. It turned out to be the plug hole had water in it. It was shorting out the wire so the engine was missing. Probably not your cause though as they would find it quickly at the dealership. Mine happened a few different times and I cleaned by pulling the wire and blowing out the hole with compressed air. It didn,t always through a code either. Good luck with it.
yeah they cleaned my throttle body i've noticed a difference in acceleration but not so much in the idle, vibration is less but still there, searched the PCM for codes, none came up, next step is try some injector cleaner and maybe take an airline to the plugs