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

O2 Sensors

Discussion in '1st Gen. Tacomas (1995-2004)' started by newbie72, Dec 9, 2022.

  1. Dec 9, 2022 at 6:49 AM
    #1
    newbie72

    newbie72 [OP] New Member

    Joined:
    Nov 23, 2022
    Member:
    #411334
    Messages:
    4
    Gender:
    Male
    Erie, PA
    Vehicle:
    2001 Tacoma PreRunner 2.7L
    Hi,
    New member and this is my first post here. Just bought the truck and I am pulling a P1135 code. Got the Denso part to replace the upstream sensor but as I was looking around, it looks like there should be a downstream sensor there as well, that is nowhere to be found. Can't imagine its supposed to be that way.

    How can that be without dropping some other code? Or I am just missing something?

    Thanks for any help/thoughts anyone can offer.
     
    Black DOG Lila likes this.
  2. Dec 9, 2022 at 7:07 AM
    #2
    Bivouac

    Bivouac Well-Known Member

    Joined:
    Sep 5, 2021
    Member:
    #376253
    Messages:
    11,582
    Northern Lehigh Valley Pa
    Vehicle:
    2000 Tacoma 5 speed 3.4
    Remains to be seen I bought the tires and wheels the rest came along
    Welcome to the Forum!

    The exciting things one might find one a 20 year old truck.

    You have crawled under the truck and looked? Some times the bung is located you can not see the sensor from the right side.

    Possible the truck has a device to send a counterfeit signal to the ECM saying the Cat or Cats are working.
     
    Black DOG Lila likes this.
  3. Dec 9, 2022 at 7:12 AM
    #3
    Black DOG Lila

    Black DOG Lila Well-Known Member

    Joined:
    Jun 14, 2019
    Member:
    #296344
    Messages:
    9,116
    Virginia
    Vehicle:
    2003 Tacoma SR5 2.7 5 speed 4WD
    Stock. EZ pass.Dump pass.Inspection sticker.Convict printed lic.plates.FG cap.
    Welcome to TacomaWorld
    Previous owner may have removed the downstream sensor and installed an illegal O2 simulator to hide P0420
    Catalytic converter efficiency below acceptable level.
    Is there a straight pipe welded in where downstream sensor should be?
     
    Bivouac likes this.
  4. Dec 9, 2022 at 7:20 AM
    #4
    newbie72

    newbie72 [OP] New Member

    Joined:
    Nov 23, 2022
    Member:
    #411334
    Messages:
    4
    Gender:
    Male
    Erie, PA
    Vehicle:
    2001 Tacoma PreRunner 2.7L
    Yeah, I crawled under and looked and felt around. Didn't know they made such devices but I am at a loss otherwise. Thanks for the input.
     
  5. Dec 9, 2022 at 7:28 AM
    #5
    newbie72

    newbie72 [OP] New Member

    Joined:
    Nov 23, 2022
    Member:
    #411334
    Messages:
    4
    Gender:
    Male
    Erie, PA
    Vehicle:
    2001 Tacoma PreRunner 2.7L
    Yes, there is a straight pipe but it didn't appear to be welded, thought it had flanges on it but I could be wrong. I didn't see any lose connector hanging free but maybe it was just tucked up out of the way. I'll have to crawl back under there again and do a deep dive.
    Any idea where such a device may be located? Just curious now.
     
  6. Dec 9, 2022 at 7:29 AM
    #6
    HondaGM

    HondaGM Call sign Monke

    Joined:
    Oct 28, 2009
    Member:
    #25056
    Messages:
    13,734
    First Name:
    James
    South-Pole, Alabama
    Vehicle:
    2023 access cab V6
    Welcome to TW....
     
  7. Dec 9, 2022 at 7:35 AM
    #7
    Bivouac

    Bivouac Well-Known Member

    Joined:
    Sep 5, 2021
    Member:
    #376253
    Messages:
    11,582
    Northern Lehigh Valley Pa
    Vehicle:
    2000 Tacoma 5 speed 3.4
    Remains to be seen I bought the tires and wheels the rest came along
    As the harness for the second sensor goes down through the cab floor under or behind the right seat .

    Things might be pulled up into the cab.

    Happy hunting.
     
    Black DOG Lila likes this.
  8. Dec 9, 2022 at 8:08 AM
    #8
    Black DOG Lila

    Black DOG Lila Well-Known Member

    Joined:
    Jun 14, 2019
    Member:
    #296344
    Messages:
    9,116
    Virginia
    Vehicle:
    2003 Tacoma SR5 2.7 5 speed 4WD
    Stock. EZ pass.Dump pass.Inspection sticker.Convict printed lic.plates.FG cap.
    Look under the 1" rubber plug on bottom of passenger side floor panel. If you can't find the simulator there, pull the door sill rocker cover (3 screws) and look under carpet for wires and connector under seat area.
     
    Bivouac[QUOTED] likes this.
  9. Dec 9, 2022 at 2:01 PM
    #9
    newbie72

    newbie72 [OP] New Member

    Joined:
    Nov 23, 2022
    Member:
    #411334
    Messages:
    4
    Gender:
    Male
    Erie, PA
    Vehicle:
    2001 Tacoma PreRunner 2.7L
    Thanks!

    Seems to be tons of information here, may a bit too much as my head is approaching full capacity already.
     
    Bivouac likes this.
  10. Dec 9, 2022 at 6:32 PM
    #10
    O'Silver_Taco

    O'Silver_Taco Well-Known Member

    Joined:
    Aug 26, 2021
    Member:
    #375390
    Messages:
    4,246
    Gender:
    Male
    First Name:
    MD
    Vehicle:
    98 Dlx Sr5 ext AT Rwd
    3rz to 2Rz bebuilt block and new heads
    ...

    IMG_0266.HEIC.jpg
     
    HondaGM likes this.
  11. Dec 9, 2022 at 6:42 PM
    #11
    O'Silver_Taco

    O'Silver_Taco Well-Known Member

    Joined:
    Aug 26, 2021
    Member:
    #375390
    Messages:
    4,246
    Gender:
    Male
    First Name:
    MD
    Vehicle:
    98 Dlx Sr5 ext AT Rwd
    3rz to 2Rz bebuilt block and new heads
    That back o2 sensor is a pig tail that plugs into the harness right there at the back of tranny...

    IMG_0265a.jpg
     
    HondaGM likes this.
  12. Dec 9, 2022 at 6:52 PM
    #12
    O'Silver_Taco

    O'Silver_Taco Well-Known Member

    Joined:
    Aug 26, 2021
    Member:
    #375390
    Messages:
    4,246
    Gender:
    Male
    First Name:
    MD
    Vehicle:
    98 Dlx Sr5 ext AT Rwd
    3rz to 2Rz bebuilt block and new heads
    Which goes up and over tranny to left side.....

    IMG_0265.HEIC.jpg
     
    HondaGM likes this.
  13. Dec 9, 2022 at 6:56 PM
    #13
    O'Silver_Taco

    O'Silver_Taco Well-Known Member

    Joined:
    Aug 26, 2021
    Member:
    #375390
    Messages:
    4,246
    Gender:
    Male
    First Name:
    MD
    Vehicle:
    98 Dlx Sr5 ext AT Rwd
    3rz to 2Rz bebuilt block and new heads
  14. Dec 10, 2022 at 6:54 PM
    #14
    O'Silver_Taco

    O'Silver_Taco Well-Known Member

    Joined:
    Aug 26, 2021
    Member:
    #375390
    Messages:
    4,246
    Gender:
    Male
    First Name:
    MD
    Vehicle:
    98 Dlx Sr5 ext AT Rwd
    3rz to 2Rz bebuilt block and new heads
    If you drive a little further around the mountain......

    .....you'll see the 4 presidents.........
     

Products Discussed in

To Top