I have a 00 F-150, W/ the 5.4 . had problems w/ misfire on #3,5 was told to change coils w/ some improvement but still some hesitation and bad gas mileage. I was told also to check for vacuum leaks on hoses. Take a can of carb cleaner and spray on hoses and fittings if you have a leak rpm should increase. HOPE THIS HELP'S....

 

yea using carb cleaner on the hoses might help find a leak, ive heard of that being done before, oh and nice name cause its my initials