Hi. I have a 2002 f150 4x4 4.6l (145k miles) that just started idling up and running rough (tune up 4 months ago w/new coils)....revs up (no foot on gas) and then drops off to idle rough or die.

codes say running lean, has new O2 sensors, MAF, and TPS.

only other thing may be timing chain or ECU dying.


Any thoughts?

thanks...

 

I know this may be too simple but my truck was doing that and it turned out to be a vacuum hose.

 

Thanks, will check the vac hoses.

 

I would agree. It may be a vaccum leak. Have you tried having a injector cleaning?