I have a 3 door98 f150 4x4 with the 4.6L v8engine...i bought it a year ago with 170,000mi and now it has 191,000 on it... it had really nice power for the first couple months and then it just started boggin real bad up hills and went from 11mi to the gal to about 8 or 9.Off the line got extremly horrible too. takes it likea quarter mile to hit 60mph from a dead stop.the power loss on this thing isridiculus.This is the work done to the truck...35 in mudders on 17in axis bead lock rims,K&N cold air in take, granitelli throttle body spacer and Granitelli high air flow mass sensor, Fabtech 6in lift, flow master exhaust system,.... This is every thing i did to the truck to figure out why or to fix my problem.... Re geared front and back diffs to 4:10, new spark plugs and wires, decarb engine, decarb injectors, checked Cats by having them takin in and O2 sensors only to find out that their all still good working condition, i cleaned the mass air flow sensor, Compression is good to.....im just out of ideas of whats wrong or how to fix it... please help...iv heard of alot of these trucks doing this before and so far the only way i hear to correct the prob is buy a new engine...i dont wanna do that... <a href="http://s126.photobucket.com/albums/p...8_edited-1.jpg" target="_blank"><img src="http://i126.photobucket.com/albums/p...8_edited-1.jpg" border="0" alt="Photobucket"></a>