I have a 2006 5.4L f-150. I just put a new magnaflow exhaust and K&N CAI on it, and have custom tunes from Troyer on the way. My question is if I should be worried about it running to lean? I've noticed now if I really hammer it and give it all shes got it sounds like the engine is missing at first and takes a second to catch up before it takes off. Otherwise with moderate acceleration it seems fine. Gonna take the K&N off tonight anyway I think.

Thanks a ton for any advice,
Zane

 

While I dont have a 5.4L, I remember reading people with similar questions, and Im sure if you did a search for the 3v 5.4L you'd find the answer but Im pretty sure it was that without custom tunes, the intake causes it to run too lean.

If I were you I'd just take it off, as you stated, good luck and hope those tunes turn out well.

 

Yes that sounds like your having a problem with it running lean. I would take it off until you get your tunes in.

 

If you leave it on, stay out of it. You are probably running lean at higher rpm. You don't get full benefit of a CAI without a custom tune anyway, so why put it on even, until you get your tunes?

 

your ECU is gonna take a little bit for it catch up....maybe a couple days. You won't have any problems with it