Page 1 of 5 1 2 3 ... LastLast
Results 1 to 15 of 63

Thread: Trouble codes p0171 and p0174.

  1. #1
    #8658, 6/3/02
    Name:

    joedpl's Avatar
    Join Date
    Sep 2007
    Location
    Edmond, Oklahoma
    Posts
    2,575
    Like
    1
    Liked 0 Times in 0 Posts

    Trouble codes p0171 and p0174.

    I took my car to the dealership today to have the oil changed and when I was driving to work today the SES light came on. Luckily I had my programmer in the truck with me and it brought up the p0171 and p0174 which is system too lean bank 1 & 2. What do I need to do to fix this, is this a problem with the 02 sensors? any info appreciated.

  2. #2
    Lovin' it
    Name:

    chupac's Avatar
    Join Date
    Jun 2007
    Location
    Los Lunas, NM
    Posts
    742
    Like
    0
    Liked 0 Times in 0 Posts
    Try cleaning your MAF.

  3. #3
    ResFirma Mitescere Nescit
    Name: stew

    bgstew6's Avatar
    Join Date
    Jun 2004
    Location
    Charleston, SC
    Posts
    18,059
    Like
    0
    Liked 0 Times in 0 Posts
    check for vacuum leaks and make sure they put your damn oil cap back on.

  4. #4
    They say im RETARDED
    Name:

    02maddness's Avatar
    Join Date
    Sep 2007
    Location
    Lewisville, Tx
    Posts
    991
    Like
    0
    Liked 0 Times in 0 Posts
    yeah deff check for a vacume leak.. i would most likely bet that its a unpluged vac line
    i did it to mine opps a while back when i did spark plugs..
    check down on the drivers side of the blower toward the front there is a lil dual vac line plug in for the blower there should b a pink i think and a red vac line.. the red vac line goes to the fuel psi thing on top of ur drivers side fuel rail..
    make sure that is pluged in that would deff cause a system to lean on bank 1 and 2 it did it too mine and deff clean ur maf and tb

  5. #5
    #8658, 6/3/02
    Name:

    joedpl's Avatar
    Join Date
    Sep 2007
    Location
    Edmond, Oklahoma
    Posts
    2,575
    Like
    1
    Liked 0 Times in 0 Posts
    I will be sure to check all that out, I'll let you know how it goes.

  6. #6
    Drivetrain Calibration
    Name:

    Ryan@RhynoTune's Avatar
    Join Date
    Feb 2004
    Posts
    1,431
    Like
    0
    Liked 0 Times in 0 Posts
    If you have a tune, it could be a bit lean in the lower part of the mass air meter table.

  7. #7
    #8658, 6/3/02
    Name:

    joedpl's Avatar
    Join Date
    Sep 2007
    Location
    Edmond, Oklahoma
    Posts
    2,575
    Like
    1
    Liked 0 Times in 0 Posts
    Quote Originally Posted by Ryan@RhynoTune View Post
    If you have a tune, it could be a bit lean in the lower part of the mass air meter table.
    I have the truck running on the stock tune right now, I took it off of the 91 octane power tune when my in-town mileage dropped from 13.3 to 10.5 so I reinstalled the original tune so I don't believe it would be that. I ran out of time this afternoon to tear into the truck but I will either tear into it tonight or tomorrow but the tradeoff was that I got to help my neighbor work on his 1911 oldsmobile. I checked the vacuum lines and all seemed to be well but hopefully it is just a dirty MAF but just to be safe I'm cleaning the throttle body and intake too. Maybe I'll do a port job while I have the throttle body off.

  8. #8
    #8658, 6/3/02
    Name:

    joedpl's Avatar
    Join Date
    Sep 2007
    Location
    Edmond, Oklahoma
    Posts
    2,575
    Like
    1
    Liked 0 Times in 0 Posts
    Well I tore it all apart this morning, the intake itself was pretty dirty, the MAF looked clean but I sprayed it out anyway and the throttle body was black/brown, it all looks alot better now. I can only imagine what the s/c and the i/c look like, sounds like another project for christmas break.

  9. #9
    Registered User
    Name:

    Black Molly's Avatar
    Join Date
    Oct 2005
    Location
    Never Never land
    Posts
    2,903
    Like
    0
    Liked 4 Times in 2 Posts
    Okay I have the same code after i had the dealer replace the left front and back cats. While they were out I had them replace the front O2 sensors that I bought of ebay. the sensors appear to be new and for my truck. the one thing that I did notice is that on my Areoforce gauge the short trim is - or very low and the long trim is at 22 to 25. I thought that I turned off the back ones with clicking turn off on the heater banks on the predator. Should I replcae the back 02's? Or try something else?

  10. #10
    Supporting Vendor
    Name:


    Join Date
    Feb 2003
    Location
    Baton Rouge, Louisiana
    Posts
    447
    Like
    0
    Liked 0 Times in 0 Posts
    Lean on both banks can be several problems.
    Have you been driving normal or hotrodding?
    Generally both front 02 sensors will not go bad at the same time.

    You really need a scanner to diagnose so you do not throw pot shots at it.

    Starting with the basics, change the fuel filter and clean the MAF
    You have covered the possible vacuum leak issue.
    Check for exhaust leaks
    I have encountered numerous fuel system problems with our trucks as well as Lightning's.
    Check your fuel pressure and check your high and low ground circuit via the fuel pump relays

    Remember, it is not a bad thing to find a competent mechanic and pay diagnostic fees. usually ~$80 to $100
    This can be much cheaper than throwing parts at it.

    Good luck,
    Vince

  11. #11
    Registered User
    Name:

    Black Molly's Avatar
    Join Date
    Oct 2005
    Location
    Never Never land
    Posts
    2,903
    Like
    0
    Liked 4 Times in 2 Posts
    sorry I think I may have tried to put too much in one paragraph I took my truck into the dealer because of the bad rotten egg smell from the exhaust. they told me it was the cats going or are bad. This was covered under the factory 70,000 mile warranty by ford. While they had the cats down I had them replace the front 02 sensors because I have hear that they are a pain to replace. Before the change the Areoforce gauge read front and back + or- 5. Now that I have it back the fronts read okay but the backs are at about +20 to 25. This is when I noticed the codes 2 times. After the first time I took the predator and I turned off the two heater banks. So should I also turn off the back o2 completely? or Is there another problem. Once again I did not see this until I had the cats and front O2 replaced. Could it be a simple MAF cleaning? or something else. I have a predator to scan.

  12. #12
    #8658, 6/3/02
    Name:

    joedpl's Avatar
    Join Date
    Sep 2007
    Location
    Edmond, Oklahoma
    Posts
    2,575
    Like
    1
    Liked 0 Times in 0 Posts
    Since I cleaned my MAF and throttle body the codes have stayed off, give it a try, it's a heck of alot cheaper than replacing the O2's especially if a dirty MAF is all that's triggering the SES light.

  13. #13
    Registered User
    Name:

    Black Molly's Avatar
    Join Date
    Oct 2005
    Location
    Never Never land
    Posts
    2,903
    Like
    0
    Liked 4 Times in 2 Posts
    so far cleaning the MAF did the trick. Thanks

  14. #14
    Drivetrain Calibration
    Name:

    Ryan@RhynoTune's Avatar
    Join Date
    Feb 2004
    Posts
    1,431
    Like
    0
    Liked 0 Times in 0 Posts
    Good to hear,

    Vince, very sound advice

    Looking for a way to say what you just did lol

    Ryan

  15. #15
    Registered User
    Name: Steve


    Join Date
    Apr 2003
    Location
    Florida
    Posts
    107
    Like
    3
    Liked 4 Times in 4 Posts
    Mine set both today I'll check the vac lines for a leak I hear what sounds like an exhaust leak and I get 10 mpg no matter how I drive.

    FWIW my understanding is that the sensors never cause this code, they are working and reading a lean condition and reporting it, its what
    the ECM uses to set that code. the source is almost always a vac line that is bad and leaking, intake leaking and changing the fuel filter is good
    as well as cleaning the MAF.

    Guess I've got a project.

Page 1 of 5 1 2 3 ... LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •