Fuel injection cleaning

[OtterbatHellcat]

DenverGP ....yep. I also would never even consider reusing the o rings on a tall mileage vehicle for the reason given.

Yeah...it ran great until it burned to the ground on the side of the highway.

[zteknik]

01 f150- 5.4? Over 100k or close to? Normally we recommend a full tune up, plugs, wires ( if coil on plugs then boots) air filter, fuel filter, pcv valve, throttle body clean and injector service- ie run some bg cleaner through the port on the rail. Standard service on these every 60k or so.
But like Kazoo said, ther may be other thins as well. Is the check engine light on? It can also be a slight vacuum leak as well. Check that by spraying carb cleaner around the lines and intake manifold and air intake tubes, you'll notice the difference in rpms if there's a leak.
Hope that helps