1. Welcome to Tacoma World!

    You are currently viewing as a guest! To get full-access, you need to register for a FREE account.

    As a registered member, you’ll be able to:
    • Participate in all Tacoma discussion topics
    • Communicate privately with other Tacoma owners from around the world
    • Post your own photos in our Members Gallery
    • Access all special features of the site

Error Code 171

Discussion in 'Technical Chat' started by S-Runner '01, Jul 10, 2010.

  1. Jul 10, 2010 at 2:30 AM
    #1
    S-Runner '01

    S-Runner '01 [OP] Elderly Gentleman - Junior Member

    Joined:
    Jul 15, 2008
    Member:
    #7943
    Messages:
    65
    Gender:
    Male
    First Name:
    Jerry
    Yakima "the Palm Springs of Central Washington"
    Vehicle:
    BSP '01 S-Runner
    Garmin 260W - GPS Scanguage II K&N FIPK Kit Delta Low Profile Toolbox Fumoto Oil Drain Valve New Toyota Front Mats B&M Short Throw shifter New Tokico Gas Shocks Compustar Anti Theft Alarm System Redline Elite Hood Struts Phase Linear DVD/MP3/CD Player Professionally Detailed
    My Check Engine Light came on while traveling on the freeway while climbing a hill. My Scanguage II tells me that the stored error code is "PO171 System too Lean (Bank 1)"
    Why would my system be too lean? What can I do to richen it up to where it's supposed to be?
    Jerry
     
  2. Jul 10, 2010 at 3:39 AM
    #2
    ShadowFalken

    ShadowFalken Well-Known Member

    Joined:
    Dec 30, 2009
    Member:
    #28480
    Messages:
    300
    Gender:
    Male
    First Name:
    Jim
    Maryland
    Vehicle:
    10 Off Road
    Raptor stainless bars, Wet Okole covers, RollBak bed cover, PopNLock, Redline hood struts, XM radio factory kit
    :popcorn:

    Get it checked out. Could be several things. Do you understand how to read scan data under regular driving conditions?

    If not, you could end up guessing and spending money without a fix.
     
  3. Jul 10, 2010 at 9:26 AM
    #3
    S-Runner '01

    S-Runner '01 [OP] Elderly Gentleman - Junior Member

    Joined:
    Jul 15, 2008
    Member:
    #7943
    Messages:
    65
    Gender:
    Male
    First Name:
    Jerry
    Yakima "the Palm Springs of Central Washington"
    Vehicle:
    BSP '01 S-Runner
    Garmin 260W - GPS Scanguage II K&N FIPK Kit Delta Low Profile Toolbox Fumoto Oil Drain Valve New Toyota Front Mats B&M Short Throw shifter New Tokico Gas Shocks Compustar Anti Theft Alarm System Redline Elite Hood Struts Phase Linear DVD/MP3/CD Player Professionally Detailed
    You say "Get it checked out." Kinda makes you sound like a Toyota dealer wanting me to "Get it checked out."
    I'm trying to check it out by posting here. Do you have an answer to my question?
    Jerry
     
  4. Jul 10, 2010 at 9:29 AM
    #4
    1337Taco

    1337Taco Slamry

    Joined:
    May 9, 2008
    Member:
    #6504
    Messages:
    7,385
    Gender:
    Male
    First Name:
    Kevin
    NorCal
    Vehicle:
    07 Tacoma Off-Road
    Camburg Spindles, Bilstein Rear plus AAL. 285 Hankook MT.
    How many miles on your truck? I would try cleaning your MAF sensor, might just be dirty.
     
  5. Jul 12, 2010 at 8:21 AM
    #5
    ShadowFalken

    ShadowFalken Well-Known Member

    Joined:
    Dec 30, 2009
    Member:
    #28480
    Messages:
    300
    Gender:
    Male
    First Name:
    Jim
    Maryland
    Vehicle:
    10 Off Road
    Raptor stainless bars, Wet Okole covers, RollBak bed cover, PopNLock, Redline hood struts, XM radio factory kit
    I did answer your question. Anything you are told on here, for that code, will be a guess. A P0171 code is set when the vehicle has reached adaptive limits for fuel control. It has added fuel to the base table until it is outside an accepted range. There can be several reasons for this. It would depend on what the fuel trims are under different driving conditions. Where the trims are out of range is the first clue to the root cause and can only be seen on a test drive with the correct equipment. Then some tests to verify the root cause and then the repair. If you toss a part at it that is a couple hundred dollars and it does not fix it, "checking it out" would be the cheaper route.

    I am not a Toyota dealer or a Toyota tech. I am a CMATL1 certified technician and an automotive diagnostics instructor.

    Sorry my answer did not fit your expectations. Guess away. Could be as simple as a clogged fuel filter, a tank of gas with a high ethanol content or as expensive as an AFR sensor or failed MAF. Pick a starting place and spend away. You said it was under high load (climbing a hill on the highway) so start with the items that would be important under those conditions.
     
  6. Jul 12, 2010 at 8:28 AM
    #6
    98tacoma27

    98tacoma27 :POOPCORN: Staff Member

    Joined:
    Dec 18, 2008
    Member:
    #11714
    Messages:
    48,163
    Gender:
    Male
    First Name:
    Ben
    Beech Creek
    Vehicle:
    05 Tundra SR5, 88 SR5 PU, 98 TRD OR (CRUSHED)
    5100's all on fours
  7. Jul 17, 2010 at 9:00 PM
    #7
    kevhogaz

    kevhogaz Low Speed, High Drag

    Joined:
    Sep 6, 2008
    Member:
    #9055
    Messages:
    324
    Gender:
    Male
    Queen Creek, Arizona
    Vehicle:
    SR5 PreRunner
    3" lift front & rear, Air Raid Intake System
    ShadowFalken is exactly right. P0171 is a system too lean code, or in laymans terms, their is too much fuel returning to the gas tank. I am a Toyota tech, and it's more than likely a Mass Air Flow Sensor malfunction. However, there are other things too check, such as vacuum leaks, before you go throwing money at your truck.
     
To Top