P0171 and P0174 -- my turn

[Coleman Brumley]

Hello. I've found this site to be very helpful in my research for buying a Sport Trac. Thank you.



I just bought a 2001 ST Job 1 and love it. She's got 134,000 miles on her, but for me it was love at first sight.



However, VERY shortly after I bought it and on a VERY cold morning I go out and start her up. Bam! Rough start, rough idle, and stalled a few times. And, the check engine light came on.



Took it to Pep Boys to get the codes read and it came up:

P0171 System Too Lean (Bank 1)

P0174 System Too Lean (Bank 2)

P0100 OBDII System Checks Incomplete



For Job 1 ST:

EDIT: My ST is an '01 Job 1, and it doesn't have the "elbow" problem. This problem was caused by the intake manifold gaskets failing. Those were replaced with Motorocraft gaskets and the codes were cleared.



I let this go for about 10-12 days and by the time the gaskets were replaced, about 7 other codes had been reported -- all related to the vacuum leak.



Just to repeat, my fix was:

1) Replace the upper AND lower intake manifold gaskets.

2) Clean the intake manifold.

3) Clean the MAF sensor

4) Clean the IAC

5) Clean the TB

6) Run seafoam through it to clean gunk.



There are projects for 3, 4, 5, & 6 on the projects page.



For Job 2 ST:

My take on the P0171 and P0174 is that a very likely cause is the PCV valve and elbow. I'm replacing those this weekend. If that doesn't do fix it, and I hope it does, I'll replace the IAC valve. Those are the two simplest and least expensive fixes. This was all of a sudden, as when I checked out the truck before buying it, the weather was cold and it didn't have these symptoms.



My question for the board is, what is the likelihood that the PCV changes (valve AND elbow) will correct this? Should I also fork over the $70 for the aftermarket IAC just in case? What about the MAF sensor?



Or am I wrong in thinking that the "order of precedence" for this problem is: PCV, IAC, and then MAF?



Also on my list of replacements is the S belt (with a Gates belt) and the belt pullies. Normal mantainance stuff, but necessary in a vehicle with this many miles.



I'm hoping these little changes really improve her and she lasts for a long time to come.

 

[Jerry Gerner 2]

Yes the elbow is the 1st suspect, $30 fix from dealer. You can save money and just clean the IAC, MAF, Throttle body. You don't have to clean all these but I found when I did all of them at once it made a world of difference. I also used seafoam in the gas tank but you can use it on the intake as well. Do a search on these projects, it'll save you tons of money. Hopefully this helps you, come mornig there'll be alot more members on to assist you if needed.:smile0006::banana::smile0012:

 

[Rodger Tellefson]

I agree with Jerry. :banana:

 

[Chris Taylor]

I'd bet money on the PCV elbow being the main problem. The others in the order that Jerry mentioned are good maintenance items, and are also the order I would do them in.



Welcome to the site!

 

[scott degroot]

How does it run/idle when it's warmed up?

 

[Coleman Brumley]

Thanks everyone. I'll let you know how this turns out.



My weekend project is to replace the PCV and the whole hoseline -- not just the elbow. I've already purcahsed both from the dealer for $55.51.



"While I'm in there" I'm going to clean the MAF with electronic cleaner or MAF cleaner. This seems like an easy thing to do.



I'll likely just swap the IAC instead of cleaning it, but only if the PCV swap doesn't fix the problem.



The seafoam thing is new to me, I hadn't come across that before. I'll look up that project too.

How does it run/idle when it's warmed up?

l1tech -- after she gets warm, she runs great.

 

[Coleman Brumley]

In the project for cleaning the IAC it says to make sure the CEL isn't on. Mine is, so should I not try to clean the IAC?

 

[Justin Bennett 2]

I hope to do the same this weekend. Assuming my dealer has the setup in stock. Although, I need the part number for the dealer. they couldn't find it or something.. after a forum search I find 2-3 different numbers. what preferred part number should I walk into the dealer with?

 

[Jerry Gerner 2]

Sounds good, Coleman, you can either disconnect the battery for about 30 minutes or take it to a parts store and have them clear the codes for you. As for the elbow and the hose asssembly it was only $30 from the dealer and they come as one unit, front elbow/ hose/ rear elbow, can't remember the exact part number for it though. :banana:

 

[Coleman Brumley]

When I called the local Ford dealer, I asked for a "PCV hoseline for a 2001 Explorer Sport Trac" after providing the motor details, they knew exactly what I needed. The line and elbows (one assembly) was $37.51. The valve was $18.00. I could have got an aftermarket valve WAY cheaper, but decided it was worth it to go with Motorcraft in this case. The next change, I'll use one from NAPA.



I just did the seafoam application, it was an absolute breeze!!! I may have used a little too much because it's still smoking a bit, but I'm sure that'll go away. I have to have a PA emissions test done on it this week, and I'm sure that'll help.



I also cleaned the MAF with CRC MAF cleaner. That was also a breeze and I just took the whole assembly off the air filter, so I didn't have to remove the MAF itself. We'll see if that fixes the rough idle when cold problem tomorrow morning! I'll still replace the PCV and hoseline for maintainance, though.



So, 2 things down, 2 to go. Clean the IAC and replace the PCV. Maybe I'll tackle cleaning the TB while I'm at it to be thorough.



Thanks everyone, and I'll keep you updated.

 

[Justin Bennett 2]

Thanks for the name of the part Coleman. I'll ask for that when I call my dealer.

 

[Coleman Brumley]

can't remember the exact part number for it though

The part #s on my invoice are:

2L5Z6A666BA --> PCV valve $18.00

4L5Z6758HA --> PCV hoseline $37.51

Total $55.51

 

[Coleman Brumley]

I may have used a little too much because it's still smoking a bit

I just went out and ran it again, and the smoke has cleared up.



Looking forward to tomorrow morning to see if cleaning the MAF solved it. I doubt it, so I'm not getting my hopes up, but that would be awesome because it was such an easy procedure.



I'm sure the PCV valve is too, but I can't seem to locate it with the cover on. And I didn't want to get into that today. I'll wait until the weekend when I can get it in a garage. :smile0004:

 

[Jerry Gerner 2]

Ok, didn't know you got the valve too, that explains the higher price, the smoke will go away. Hopefully these these will fix the rough idle, it did on mine. :smile0012:

 

[Coleman Brumley]

Ok, so I'm thinking my ST may be a Job 1. It's got the bigger plastic cover (I thought Job 1 had an aluminum cover?). On the Job 1, the PCV elbow doesn't exist, does it? Now what???

 

[EddieS'04]

coleman if your oil filler neck is on driver valve cover. It is a job 1.

 

[Coleman Brumley]

if your oil filler neck is on driver valve cover. It is a job 1.

Yep, just checked and it is -- so it's a Job 1. Looks like the simple PCV fix won't work for me??? So, time to look a the IAC and TB I guess.



Anybody want a Ford PCV hoseline and valve? I sell them at my cost! LOL.

 

[Coleman Brumley]

Is there even a PCV valve on the Job 1 ST?

 

[Kevin Palmer]

Coleman,



Job 1 Trac's with the codes you have are often the intake gasket creating the vacuum leak.

 

[Todd Z]

Job 1 PCV is burred on the back of the motor about center in a hose. You can get to it from up top, just a pain..



Sounds like your intake manifold gaskets are toast..



Todd Z