I've searched and haven't found much help... I have the dreaded p0171 and the p0174 codes. From what I've read, the most likely cause is the vacuum line coming off the bottom of the intake manifold in the back. Problem is... there is no room to get my hand in there. I followed the PCV line from the passenger side and it appears the line is attached more on the drivers side of the manifold.

Has anyone replaced this elbow before and if so, how the heck did you get to it?

My inspection is up this month and I need to get this fixed.

https://www.f150online.com/forums/sh...ighlight=p0171

 

I replaced mine while I had the sc off to clean the ic and change plugs. I couldn't get my hand/forearm back down there to get the old off and put the new on otherwise. The new hose with PCV is part #YL3Z*6C324*BA.

 

Ditto - I had my s/c and intercooler off to clean when I capped the on the lower intake to install breathers..I don't see how you can do it any other way..

I just found a cause of my lean codes, one of my cap boots on the inlet tube was cracked open. I may get lucky and that solve the problem..

 

i have code P0171 but not 0174. i havnet had time to look for the problem yet , but my question is. will it hurt the truck to be driven daily until i can get it fixed? and when i mean driven, i mean just normal like grandma would drive.

as far as the problem , i am sure its a vaccum leak because i can hear it but i cant find it to save my life.

 

I drove mine for weeks before I fixed it. You're running lean so watch the WOT runs.

 

Well... I got my hand back there and could feel the hose. It is weak and spongy... more than likely this is my problem.

Anyone got a pic of the lower intake? It may be a moot point since I think I am going to have to pull the SC to get to the hose regardless.

Hey... I got 103k on it... it's about time I cleaned the SC anyways. Just wish I had a ported one to go back on.

And yes... I'll put an Oil Separator kit on.

 

Hi Rick,
I just got thru dealing with the same issue on my 98 Navigator. I managed to get the rear hose off by first removing the IAC. Stuff a rag under the IAC first so you don't loose the gasket. You'll need a quarter inch ratchet with a 8mm socket, and even then it's not easy. Once off I fixed it with a gob of black silicone sealer as it looks like a rather expensive vacuum line.
Knowing what I know now, I'd try getting a gob of sealer back under that fitting without removing it or the IAC. The leak is no doubt under the elbow and if you lie down facing the engine you sort of hug your way back there. A step stool helped me. Do a dry run first. Then put the gob of sealer on one finger, locate the fitting with the same finger on the opposite hand. Bring the gobbed finger in and do it. It's easier if you're trying to meet your other finger. Next help me locate the cheap b*st*rd at Ford responsible for those cheap rubber fittings. I'd like to know if he's being paid by Toyota to cheapen the image of our American made stuff. Glad to help. This post has been helpful to me. Forgot to add; Don't forget to unhook your negative battery cable for 10 or 15 minutes. Your computer has gotten used to running with that vacuum leak and has to be initialized, or you may experience stalling at warm idle. Good luck, and sorry if I've repeated advise from other members.

 

Great advice... I apprecaite it. One of the guys in my area has done this before and said he'd help me.

Worst case is I pull the SC and clean the oil out it while I am there.

 

Ya know what, I think you may have pointed out where my problem is as well. I've been searching high and low for whats causing my lean codes. When I get a chance next im going to check it out.

 

Did you find it? I haven't changed mine yet but will soon. Just thought I'd see if you got it corrected yet.

 

Unfortunatly i'm having the same problem you have with getting to the vacume line and then some. I have the shaker hood on my truck and the scoop being bolted to the upper plenum makes it rather hard to reach around to the back of the lower intake. I don't really drive my truck that much, I ride my bike mostly, so when I get the time to pull the scoop off i'll let you know.