I have a 05 ford f150 with the 5.4L engine 3v and is a 4x4. Lately the truck has been HORRIBLE AND GETS 6-8 MPG and looses power at 70 mph won't accelerate more then 80 mph and RPM fluctuate feom 2750-3k-3500 rpm when hitting 70mph and above it sounds lIke it has trouble pas sing gears but no hard shift or pulling. You have to play with gas pedal to get gear at lowere rpms. THEY GAVE ME THESE CODES AT O'REILLYS: p0060: o2 sensor, p012 6/0: below resolating temp, p0021 cam sensor. Also bought a fuel filter and going to put it on. Replaces catalytic converter on passenger since it had straight pipe and noticed catalytic on driver had 1 conection disconected si I connected it back. Also this trucks check engine light won't turn on even if there is something wrong with truck. Any help would be nice

 

how many miles on this motor and when was the last tune-up.. any maintenance history would help. sounds like it needs some exhaust work..

 

134k miles and bearly bought it will change out spark plugs asap and make oil change but main problem is there is no CEL even when I put key foward engine off. This is what concerns me also. I think guy that sold it to me messed with engine light to sell it other then bad mpg and not acceleration past 75 truck accelerates good at a speeds below 75

 

Dirty engine oil is used to hydraulically move the cams . The PCM electrically commands the VCTs to release oil pressure to chambers in phasors thereby moving cams . Trouble is the screens and small passages clog up with combustion carbon .
Oil pressure is key and this engine bad about blown plastic tensioner seals that will lower oil pressure . Making it even harder to move phasors . Tensioners rely on oil pressure to control chains , chains lose tension and whip breaking plastic guides . Guide pieces fall to oil pan clogging oil pu screen causing more oil pressure problems . Lash adjusters /rollers get starved for oil creating more noise . One of the best things to do is drop oil pan and look for plastic ,if there a complete timing job is called for .
Using old style metal ratcheting tensioners with no seals to blow out is the thing to do they still make them .
Of course the oil loss is rough on the phasors so they should be replaced with oem only . New VCTS are a better design and old ones get varnished up so change them also ,some people change out VCTS first . That's good as they usually are still good alter for timing job .
Stick with mc filters as they have a better anti drain back valve . Use of a heavy oil is detrimental and causes other problems . You might as well pour saw dust in there like they used to do to quiet an engine for sale .
Use full syn and change often . I like to use a little Marvel mist oil .
Oh! and your oil pressure gauge is crap it reads mid scale if above 7 psi .

 

Do they not do emissions testing where you are? Just curious.