Possibly 1 or more of the injector spill off pipes have not been refitted correctly, alot of people (especially non-ford dealers) push them in and think thats them as the clip will still go on but they need to be pushed fully home!
Or sometimes the little o-ring seals snap when the spill off pipes are removed, possibly been refitted without noticing!
this is just 1 of a number of possible problems..
might require a PCM update, air filter blocked, possibly an EGR issue, etc etc..
might sound daft but none of your brakes are binding on?
first thing i would do would be to give it a good old fashiond rag haha!
then if nothing changes i would take it back to where u got it repaired or to a ford dealer as they will probobly find the fault much quicker then if something flags up that relates to the repair that place carried out take it back and demand it is fixed!
hope this helps u a bit m8!