my 06 has a 5.4 and was running bad took it to dealer and they checked and said I need a new enigine. I asked what was wrong they said it was jut bad. took it to another local shop and asked them to check it out, not sure what they did but they said the same thing. I brought it home and done some checking, i.e new cam sensors, new vct solenoids, new timing chains and tensioners. the engine still ran bad. I done some research and found that they had a problem with the cam phaser supports on the heads loose oil pressure and don't let the timing advance. so I replaced the engine and had the ecm checked and repaired, still runs like crap. I can start and run the truck with #1,2,3 cylinder injectors and coils unplugged and the egine doesn't change. unplug any other cylinders and the engine runs worse? if any one has been through similar problems and found the answer to fixing the engine please let me know.

 

Do u Fix the problem?

 

no i'm still working on it. I just removed all the aftermarket alarm system to see if it was interfering with the eay it runs?

 

Any update?