I recently bought an 04 F-150 with the 4.6, when I was test driving it it drove great, I took it home it drover great. I took it to the dealer to have some items taken care of that I had worked into the deal. Well while they were doing the work they changed out the battery and alternator now when I'm sitting at a light I can feel a rough idle through my seat, this also seems to be influenced by whether or not the brake pedal is pressed. What are the possible causes for something like this, the only engine related work that was done was the batt and alt.

 

If you had the battery changed, unless they used a jumper wire the computer has reset. Give it some time to relearn before you go tearing into it.

 

how long should that take?, I've driven it about 150 miles since then

 

150 miles, that should have been long enough to Re-learn the computer again, But i could be wrong...

 

Maybe they knocked a wire/hose loose. I'd take it back and let them figure it out as they should do it for free.