I have a 01 F150 with 65,000 miles on it. itfelt like it was only running on 4 cyl. took it to the dealer- they said it needed plugs' wires' and a coil. replaced all that and it still has the same problem. could it be the fuel filter?

 

Not sure, but it would be a good idea to rule it out. You can do it yourself with a $17 fuel line removel tool from NAPA. (30-50 min).

Also cleaning your MAF will help. (2 min) Here is a link that explains it:

https://www.f150online.com/forums/sh...hreadid=109024