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

Code P0420

Discussion in '1st Gen. Tacomas (1995-2004)' started by t0p_d0g, Jan 17, 2025.

  1. Jan 17, 2025 at 9:25 AM
    #1
    t0p_d0g

    t0p_d0g [OP] 私はタコマが大好きです

    Joined:
    Apr 17, 2023
    Member:
    #422653
    Messages:
    1,978
    Gender:
    Male
    Vehicle:
    2023 TRD SPORT 4X4 DCSB CSM, 2004 TRD OR DCSB IRP
    My 2004 TRD OR 3.4 260K miles CEL code P0420, I cleared it 300 miles ago and it still hasn’t come back. Should I be concerned?
     
  2. Jan 17, 2025 at 9:26 AM
    #2
    02hilux

    02hilux What do you mean there’s no road, I’m here

    Joined:
    Sep 14, 2016
    Member:
    #197244
    Messages:
    6,357
    Planet: EARTH
    Check for exhaust leak, most common
     
    Area51Runner and t0p_d0g[OP] like this.
  3. Jan 17, 2025 at 9:27 AM
    #3
    t0p_d0g

    t0p_d0g [OP] 私はタコマが大好きです

    Joined:
    Apr 17, 2023
    Member:
    #422653
    Messages:
    1,978
    Gender:
    Male
    Vehicle:
    2023 TRD SPORT 4X4 DCSB CSM, 2004 TRD OR DCSB IRP
    Thanks
     
  4. Jan 17, 2025 at 9:27 AM
    #4
    eon_blue

    eon_blue If I would, could you

    Joined:
    Mar 4, 2016
    Member:
    #180213
    Messages:
    69,965
    Gender:
    Male
    First Name:
    Ryan
    Azusa, CA
    Vehicle:
    '04 TRD 3.4l 4x4 5sp manual Xtraca & '96 4runner 4x4 5spd manual
    It will come back. When you force clear a code it resets the emissions monitors to clear them. Once your truck completes (or tries to complete) the next emissions cycle it will return. That code comes and goes until eventually it just stays on. Most likely you need new catalytic converter(s) or have an exhaust leak. With trucks this old and high mileage it could be either or both, gotta do some digging to find out.
     
    Last edited: Jan 17, 2025
  5. Jan 17, 2025 at 9:40 AM
    #5
    t0p_d0g

    t0p_d0g [OP] 私はタコマが大好きです

    Joined:
    Apr 17, 2023
    Member:
    #422653
    Messages:
    1,978
    Gender:
    Male
    Vehicle:
    2023 TRD SPORT 4X4 DCSB CSM, 2004 TRD OR DCSB IRP
    Thanks for the fast response! I have noticed what sounds like an exhaust leak coming from the left side of the engine I guess I need to see if I have a cracked manifold or just loose exhaust pipe connector.

    It’s not a bad leak just slightly noticeable.
     
  6. Jan 17, 2025 at 9:55 AM
    #6
    Andy01DblCabTacoma

    Andy01DblCabTacoma Well-Known Member

    Joined:
    Mar 12, 2021
    Member:
    #359086
    Messages:
    3,998
    Gender:
    Male
    First Name:
    Andy
    San Diego, CA
    Vehicle:
    01 Double Cab v6 4x4 TRD
    F: Kings SPC, R: 5100s+J59s. Custom armor.
    I had to replace most of the exhaust gaskets around 150k cause they were leaking out of the unions in the exhaust system. I was lucky enough to take my time and not break any studs when doing the work, but it's one of those jobs where you are constantly one bad move away from a huge ordeal.
     
  7. Jan 17, 2025 at 10:00 AM
    #7
    t0p_d0g

    t0p_d0g [OP] 私はタコマが大好きです

    Joined:
    Apr 17, 2023
    Member:
    #422653
    Messages:
    1,978
    Gender:
    Male
    Vehicle:
    2023 TRD SPORT 4X4 DCSB CSM, 2004 TRD OR DCSB IRP
    I live in the South so my truck is not rusted any more than expected I will hit them with penetrating oil and hope for the best.

    Thank you very much!
     
    1 Limited Toyota likes this.
  8. Jan 17, 2025 at 10:30 AM
    #8
    ztwatson

    ztwatson Well-Known Member

    Joined:
    Dec 6, 2021
    Member:
    #383995
    Messages:
    1,001
    Gender:
    Male
    Milwaukee, WI
    Vehicle:
    2004 Tacoma TRD Xtra Cab
    Another vote for it likely being an exhaust leak. Was the case for me, between rear CAT and rear O2 sensor.
     
    t0p_d0g[OP] likes this.
  9. Jan 17, 2025 at 11:33 AM
    #9
    t0p_d0g

    t0p_d0g [OP] 私はタコマが大好きです

    Joined:
    Apr 17, 2023
    Member:
    #422653
    Messages:
    1,978
    Gender:
    Male
    Vehicle:
    2023 TRD SPORT 4X4 DCSB CSM, 2004 TRD OR DCSB IRP
    Did you have to replace a gasket or just tighten it up?
     
  10. Jan 17, 2025 at 12:36 PM
    #10
    beenexposed

    beenexposed Member

    Joined:
    Nov 11, 2013
    Member:
    #116341
    Messages:
    14
    Gender:
    Male
    Nomad
    Vehicle:
    02 taco trd 4x4 with dents
  11. Jan 17, 2025 at 4:00 PM
    #11
    ztwatson

    ztwatson Well-Known Member

    Joined:
    Dec 6, 2021
    Member:
    #383995
    Messages:
    1,001
    Gender:
    Male
    Milwaukee, WI
    Vehicle:
    2004 Tacoma TRD Xtra Cab
    The leak was from rust and the original gasket/mount was long gone by that point so I had someone just weld up where it leaked and that fixed it.
     
    Last edited: Jan 17, 2025

Products Discussed in

To Top