OK,

For over two years I've been having the P0171/P0174 error codes. Several trips to my local Ford yielded nothing other than a warning that I'd be paying for the repairs due to having an Air Raid CAI.

I'm now out of warranty and still having this error which I see is commonly solved with the replacement of the PCV Elbow. Question, for my year/model where is this elbow located? I am guessing it is the one that goes from the Passenger Side Valve Cover to the Rear of the Air Intake Tube (above the throttle body). Mine is not a rubber boot but more like a mechanical clip-in unit that's not all too snug.

Also, inspecting the hoses I noticed a hose (with some type of sensor) that originates from the Intake Manifold (passenger side of throttle body) and travels around the back of the throttle body along the firewall to what looks like some form of coupler/sensor on the drivers side. This hose is falling apart and wondered what it was.

If you could help with part numbers or pictures I'd be greatful. Most of the PCV posts I've seen are pre-2004 style. Local Ford Dealership not all that helpful and either was the local 3rd parties.

If there is a source that has a diagram of my vacuum system I'd love to get my hands on it - or someone who can.

Thanks in Advance!

 

i dont think the 5.4 3v has a pcv elbow

 

Does it set any codes with the stock airbox in place?

 

One of the 1st thing's I did when I bought my truck was, I went and bought a repair manual for my F150 at a local auto parts store. I knew it needed some work and I had the same codes. The diagram your looking for will be in the manuals, and in great detail.
Rule of thumb for me, buy a used vehicle, register it, have it inspected, and buy a repair manual. As soon as my wife's Toyota is out of warranty, I will be buying a manual.
Good luck with the repair concerning those codes. Alot of possible fixes.
Mine came down to, replaced the PCV assembly (Ford part), included rubber elbow boot to the throttle body, and thoroughly cleaned my MAF sensor. I havn't had my code return in 7 months.

 

Excellent point !!!

 

Well I fixed my problem. With the Airaid CAI and the DiabloSport Predator I learned I needed to change the MAF Curve to an increase of 5%. No error codes for well over a week and seems to be running well.