Yet another P0171/P0174 thread, Help at my wits end! - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars
Ford Forum Ford Forum

» Auto Insurance
» Featured Product
ยป Wheel & Tire Center

Go Back   Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars > Ford Trucks | Utes | Vans |SUVs | Crossovers > Ford Expedition Forum | Lincoln Navigator Forum
Register Home Forum Active Topics Photo Gallery Auto Loans Garage Mark Forums Read Auto Escrow

Ford Expedition Forum | Lincoln Navigator Forum Forum for discussion of the Ford Expedition and Lincoln Navigator.

FordForums.com is the premier Ford Forum on the internet. Registered Users do not see the above ads.
Reply
 
LinkBack Thread Tools Display Modes
Old 03-06-2013, 16:41   #1 (permalink)
Registered User
 
Join Date: Mar 2013
Posts: 3
Yet another P0171/P0174 thread, Help at my wits end!

Hi Everyone, long time lurker first time poster in need of some serious help.
I'll try and make this brief but as detailed as possible. Ive got an '02 Navigator that Ive owned for about a year, 150k miles and up until 2 days ago was running great!

My wife's car is in the shop so I let her use the Navigator to run around doing some shopping etc, When she returned home she stated that the car was "not driving right", after several questions she said she wasn't paying attention and didn't realize the truck was low on gas till the light came on and then she filled it with 87 octane again without thinking.

I took the truck out and it felt like it had a miss and the check engine light was on, I pulled out my scanner and it was showing codes P0171 and P0174.

I checked for a vacuum leak first thing and found a small one in an elbow and replaced it, no change. I then replaced the fuel filter thinking that perhaps she had picked up some crude from running the tank so low, no change. Took the car in and had a fuel injector cleaning done, thinking maybe some dirt was clogging an injector. The car ran worse. It idles with a lope, part throttle acceleration as well as cruising in the 40-55mph range results in a severe shudder, full throttle acceleration is surprisingly smooth tho..

I then decided to clean the MAf, no change so I replaced the MAf and the PCV valve, again no change.

At this point I'm clueless, the only codes being thrown are a constant P0171 and P0174, I am about 95% positive I have checked and re-checked every vacuum line I have found and still running like crap. I've also read every thread with P0171 or P0174 in this forum and haven't come up with anything that I haven't already checked.

Could it be the fuel pump? fuel pressure regulator? Any easy tests to figure this out?

Any and all help is appreciated at this point, thanks for reading!
Krichek is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 03-06-2013, 17:36   #2 (permalink)
2002 F150 XLT
 
Bert's Avatar
 
Join Date: Nov 2008
Location: Oregon
Posts: 9,726
Re: Yet another P0171/P0174 thread, Help at my wits end!

What engine is in it?
__________________
Bert
Bert is offline   Reply With Quote
Old 03-06-2013, 17:53   #3 (permalink)
Registered User
 
Join Date: Mar 2013
Posts: 3
Re: Yet another P0171/P0174 thread, Help at my wits end!

Quote:
Originally Posted by Bert View Post
What engine is in it?
The 32V 5.4L, I don't think any other engine was offered in the Navigator in '02.
Krichek is offline   Reply With Quote
Old 03-07-2013, 09:11   #4 (permalink)
2002 F150 XLT
 
Bert's Avatar
 
Join Date: Nov 2008
Location: Oregon
Posts: 9,726
Re: Yet another P0171/P0174 thread, Help at my wits end!

You're right, that's the only engine offered. How was the vacuum line at the PCV? They often are soft and when the engine is running, they leak. See if the EGR is slightly stuck open too.
__________________
Bert
Bert is offline   Reply With Quote
Old 03-07-2013, 12:45   #5 (permalink)
Registered User
 
Join Date: Mar 2013
Posts: 3
Re: Yet another P0171/P0174 thread, Help at my wits end!

Quote:
Originally Posted by Bert View Post
You're right, that's the only engine offered. How was the vacuum line at the PCV? They often are soft and when the engine is running, they leak. See if the EGR is slightly stuck open too.
One hose from the PCV valve had a small hole in it, it was the 90 degree elbow piece. The dealer didnt sell the piece individually so I replaced the whole collection of hoses as well as the PCV valve.

I had thought about the egr valve, but I honestly have no idea where it is located at and nothing looks anything like any egr valve I have seen in the past. I picked up a repair manual but it doesn't show a picture of it or state where it is located at lol.. Any idea?

Thanks also for the replies.
Krichek is offline   Reply With Quote
Old 03-07-2013, 14:06   #6 (permalink)
2002 F150 XLT
 
Bert's Avatar
 
Join Date: Nov 2008
Location: Oregon
Posts: 9,726
Re: Yet another P0171/P0174 thread, Help at my wits end!

http://ww2.justanswer.com/uploads/fo...80813_egr2.gif
__________________
Bert
Bert is offline   Reply With Quote
Sponsored Links
Advertisement
 
Reply

  Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars > Ford Trucks | Utes | Vans |SUVs | Crossovers > Ford Expedition Forum | Lincoln Navigator Forum



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Powered by vBadvanced CMPS v3.2.2

All times are GMT -7. The time now is 12:29.



Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Relevant URLs by vBSEO 3.6.0
Garage Plus vBulletin Plugins by Drive Thru Online, Inc.