hey guys.
new to me 05 fx4 5.4


are these trucks slugs?
ive been in 6cyl pick ups that pulled harder
truck runs smooth no check engine lights but it just seems to be lacking power

plugs have been changed
air filter is new
cleaned throttle body
cleaned maf
has new cats and exhaust :previous owner: no discoloration not even a speck of surface rust,so i dont think cats are clogged
i removed the muffler and put on a pypes race pro i had sitting around and that didnt make any difference, i thought maybe the muffler they used was restrictive
would there be a component failure that wouldnt throw a code?

 

They are heavy as hell. Buy a tuner, it helps a little.

 

You would get 22 rwhp and 20 feet of torque gains with a SCT unit. But the 5.4 is a good engine but it's not a fast one by nature either

 

11.6 mpg driving easy, town roads/good amount of highway 65 mph
if something wasnt right would it throw a code?