codes p0174 p0171 need help!

[gearhead06]

codes p0174 p0171 lean conditions banks 1 and 2, so I know a good deal about auto mechanics but this ones got the best of me, I recently purchased a 2001 for explorer 4.0 V6 4x4 sport, and on a could day the engine will start run extremely rough and stall once or twice and it starts right up, but on a warm day it fires up with no hesitation, I have replaced the idle control sensor, cleaned and inspected the mass air flow sensor, replaced the upper intake mani gaskets, replaced a leaking thermostat housing, checked for vacuum leaks, and ran some strong fuel system cleaner threw the entire system, I tried looking up a fuel regulator for this vehicle and nothing came up, the last two things I can think of are a fuel pump or regulator, anyone have any other ideas?

 

[jremington59]

Possible solutions include:

•In the vast majority of cases, simply cleaning the MAF sensor does the trick. Consult your service manual for it's location if you need help. I find it's best to take it off and spray it with MAF cleaner. Make sure you are careful not to damage the MAF sensor, and make sure it's dry before reinstalling
•Inspect all vacuum and PCV hoses, replace if necessary
•Check for a dirty fuel filter and proper fuel pressure

 

[swshawaii]

OBD Codes P0171 and P0174


This code is a common code to the Explorer Sport and Sport Trac. It is normally the elbow that is located under the throttle body. It tends to crack on the bottom and needs to be removed to examine it.
You can replace it with a small piece of heater hose that is 5/8 inch. But heater hose is a quick fix.
The hose will soften and collapse causing other problems. We recommend you purchase a PCV elbow or the replacement part form a dealer.

(Motorcraft KCV 190)

 

[gearhead06]

alright I will check that out, keep any tips or advice coming...

thanks

 

[swetrid]

Lower intake gaskets cause the symptoms you are having, the orings shrivel up cold and then dont seal.

 

[unpredictable1]

Lower intake gaskets cause the symptoms you are having, the orings shrivel up cold and then dont seal.

This is what I thought it was too, since I did some archive searching because I have these codes too.

 

[gearhead06]

yea I had it in the shop to get the thermostat housing replaced and the upper and lower intake gaskets replaced, the mechanic told me the lower one was not leaking and just replaced the upper gasket...

 

[unpredictable1]

Opps sorry, I meant to say upper too. Most times it's the upper from what I read.

 

[gearhead06]

yep and i had that one replaced.. does anyone think it might be anything other than the lower intake mani gasket, like I said my mechanic said it wasn't leaking...

 

[gearhead06]

ok so I can reset my computer with my scan tool and even on a warm day it will start ok and drive fine but even with 20+ miles on a warm engine it will still throw the lean codes, so I dont think its a leaking gasket issue, so I'm stumped I haven't detected any leaks anywhere... anyone else have any ideas?

 

[gearhead06]

hey swshawaii, were is this elbow you are talking about? I took a look today and didn't see any elbow below the throttle body... any pointers?

thanks

 

[swshawaii]

See post titled "Sport Trac with a PO174 code" Flangeman dated 1/12/11.

Another is "po171 po174 lean code with low idle? black smoke?" from 3/6/11

ncranchero (SteveM) posted replies with pictures of the PCV elbow on both.

Crack almost always occurs on the underside of the hose, providing you have the same engine. (SOHC 4.0)

I have also heard of a faulty ignition coil causing this code. Good Luck.

 

[gearhead06]

i searched both of those posts and nothing came up? no sure what I'm doing wrong... do you have a link or something..

thanks

 

[swshawaii]

Visit MySportTrac.com and search "PCV Elbow" all posts.

 

[gearhead06]

nope my 01 explorer sport doesn't have that elbow, o well worth a shot.. so mani gaskets, maf sensor, idle control sensors, and system checked for vacuum leaks, all have been checked or replaced, so were to next?

 

[gearhead06]

when you start the engine for the first time it shacks and stutters and on really cold days its worse, but even on a warm day or with a warm engine you can reset the codes and they will still be thrown after a little driving...

 

[Chris1973]

codes p0174 p0171 lean conditions banks 1 and 2, so I know a good deal about auto mechanics but this ones got the best of me, I recently purchased a 2001 for explorer 4.0 V6 4x4 sport, and on a could day the engine will start run extremely rough and stall once or twice and it starts right up, but on a warm day it fires up with no hesitation, I have replaced the idle control sensor, cleaned and inspected the mass air flow sensor, replaced the upper intake mani gaskets, replaced a leaking thermostat housing, checked for vacuum leaks, and ran some strong fuel system cleaner threw the entire system, I tried looking up a fuel regulator for this vehicle and nothing came up, the last two things I can think of are a fuel pump or regulator, anyone have any other ideas?

Had the same two coats a couple of months ago. All I had to do is change out the camshaft sensor and that fixed it. But I also changed the crankshaft sensor and the map sensor just to get all three done. Truck ran perfect codes were gone.

 

[410Fortune]

11 year old thread

I have never seen 171 and 174 fixed with a camshaft sensor unless you re sealed the intake O rings at the same time or fixed a leak in your air intake..........
There IS NO MAP SENSOR ON THESE FORDS AFTER 1990
a MAS or MAF yes, but no MAP