2002 5.4L looses power/torque at higher rpms... kinda just sits there.

Any ideas?

 

Have you ever cleaned the throttle body?

 

The MAF sensor and Air cleaner as well, - fuel filter ? How are you on maintenance ? PCV valve been up dated lately, -with a Motorcraft OEM part?

I would look towards maintenence parts first and go from there. What is your warm idle rpm's, -exactly ? What kind of spark plugs are you running?