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

Combination of Error Codes

Discussion in '1st Gen. Tacomas (1995-2004)' started by brogers, Jul 9, 2010.

  1. Jul 9, 2010 at 12:32 PM
    #1
    brogers

    brogers [OP] New Member

    Joined:
    Jul 9, 2010
    Member:
    #39974
    Messages:
    3
    Gender:
    Male
    Atlanta
    Vehicle:
    01 4WD Tacoma 4cyl
    Any ideas about what may be going on here? Thanks for any help! (I also posted this in the Technical section, apologies for posting in multiple forums - not sure which is best for this question).

    2001 Toyota Tacoma 4WD, 4cyl 2.7L, 110 K miles

    The check engine light came on -- codes were P0125 and P1135. I reset the light by disconnecting the battery cable and drove a couple of miles. When the light came back on, a new code appeared P0171, the other codes did not come back up.

    The following was done:
    1. Removed and replaced spark plugs
    2. Cleaned the MAF sensor
    3. Replaced the air filter
    4. Reset the light

    Then I drove the truck, the light came back on, one code: P0125

    1. Replaced the thermostat (actually looked fine)
    2. Replaced the ECT sensor (could that have been in a tougher place to get to?)
    3. Refilled the coolant
    4. Reset the light

    Then drove the truck -- the light came back on, this time only P0171.

    1. Checked for coolant leaks
    2. Found that I had knocked the vacuum line off from the air intake, reconnected it.
    3. Reset the light

    Drove the truck, light came back on. This time all three codes came up: P0125, P1135, P0171.

    Any suggestions for the next step?
     
  2. Jul 10, 2010 at 8:18 AM
    #2
    03redtaco

    03redtaco Well-Known Member

    Joined:
    May 10, 2010
    Member:
    #36903
    Messages:
    90
    Gender:
    Male
    First Name:
    Richard
    Myrtle Beach SC/ Starke FL
    Vehicle:
    03 Tacoma Prerunner SR5 DC 3.4L
  3. Jul 10, 2010 at 8:21 AM
    #3
    chris4x4

    chris4x4 With sufficient thrust, pigs fly just fine. Moderator

    Joined:
    May 8, 2008
    Member:
    #6497
    Messages:
    112,751,503
    Gender:
    Male
    First Name:
    FlimFlubberJAM
    Tenoe, AZ
    Vehicle:
    2019 Rubicon 4 Door,
    4.10 gears, sliders, and lots of buttons.
    I would replace the air/fuel and O2 sensors.
     
  4. Jul 10, 2010 at 1:56 PM
    #4
    biggdog747

    biggdog747 Well-Known Member

    Joined:
    Mar 7, 2010
    Member:
    #32729
    Messages:
    57
    Gender:
    Male
    MI
    Vehicle:
    taco
    X2
     
  5. Jul 31, 2010 at 11:00 AM
    #5
    Andruck

    Andruck New Member

    Joined:
    Jul 31, 2010
    Member:
    #41020
    Messages:
    1
    Gender:
    Male
    North Carolina
    Vehicle:
    2001 Tacoma
  6. Oct 25, 2020 at 7:11 PM
    #6
    thehadmatter

    thehadmatter Member

    Joined:
    Jan 1, 2016
    Member:
    #173680
    Messages:
    22
    Gender:
    Male
    Charlottesville, VA
    Vehicle:
    2001 EXT CAB SR5 2RZ-FE 5spd 2WD
    I just had this same issue occur and all my diagnostics point to the A/F sensor but part of me wants to smoke test the intake. Should I smoke test or just replace the sensor?
     
  7. Nov 21, 2020 at 6:36 AM
    #7
    thehadmatter

    thehadmatter Member

    Joined:
    Jan 1, 2016
    Member:
    #173680
    Messages:
    22
    Gender:
    Male
    Charlottesville, VA
    Vehicle:
    2001 EXT CAB SR5 2RZ-FE 5spd 2WD
    I smoke tested the intake and found a small leak at the aftermarket PCV hose to my cheap Chinese oil catch can. If you spend over $30 (shipping included) on a catch can then you're wasting your money. I tightened up that hose, cleared codes, and test drove. The lean code went away but the coolant temp and A/F codes came back. Replaced A/F sensor Denso part number 234-4189, Toyota part number 89465-09330, cleared codes, test drove and the cel remained off. Truck ran better too. Be prepared for seized/corroded fasteners holding the A/F sensor in place and have M8x1.25 COPPER flange nuts to replace the fasteners that are in place. You may have to grind or torch them off. Good luck and happy torching!
     
  8. Nov 21, 2020 at 5:09 PM
    #8
    Thomas670

    Thomas670 Well-Known Member

    Joined:
    Oct 11, 2020
    Member:
    #343506
    Messages:
    329
    Gender:
    Male
    Vehicle:
    2002 Taco Regular 5 speed
    P1135 is the air and fuel sensor. get denso brand i learned my lesson buy cheap brand ones
     

Products Discussed in

To Top