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

Check Engine Light ON + Cat System?

Discussion in '3rd Gen. Tacomas (2016-2023)' started by Tacoma#5150, Jul 11, 2025 at 2:48 PM.

  1. Jul 11, 2025 at 2:48 PM
    #1
    Tacoma#5150

    Tacoma#5150 [OP] Well-Known Member

    Joined:
    Aug 8, 2020
    Member:
    #337025
    Messages:
    66
    Gender:
    Female
    Vehicle:
    2020 Tacoma Off Road
    2020 Tacoma 132,444 miles. Toyota Service Center did a diagnostic on my truck and it coded the Catalyst System Efficiency Below Threshold Bank 1 and Bank 2. Since there is an upstream and a downstream all four need to be changed for $6802.56. Any thoughts on this information? Thanks in advance
     
    Last edited: Jul 11, 2025 at 4:32 PM
  2. Jul 11, 2025 at 4:28 PM
    #2
    Phlogiston

    Phlogiston There are no victims, only volunteers.

    Joined:
    Jan 15, 2020
    Member:
    #316170
    Messages:
    1,973
    Gender:
    Male
    First Name:
    A@!#$@$%#$%
    The wild west
    Vehicle:
    2016 SR5 DCSB
    Who is "They"?
     
  3. Jul 11, 2025 at 4:30 PM
    #3
    Tacoma#5150

    Tacoma#5150 [OP] Well-Known Member

    Joined:
    Aug 8, 2020
    Member:
    #337025
    Messages:
    66
    Gender:
    Female
    Vehicle:
    2020 Tacoma Off Road
    Toyota Service Center I just edited my original post
     
  4. Jul 11, 2025 at 4:35 PM
    #4
    Phlogiston

    Phlogiston There are no victims, only volunteers.

    Joined:
    Jan 15, 2020
    Member:
    #316170
    Messages:
    1,973
    Gender:
    Male
    First Name:
    A@!#$@$%#$%
    The wild west
    Vehicle:
    2016 SR5 DCSB
    I know CATs can be expensive but $6800 sounds pretty high.
    I've never had to replace mine so i can't compare costs but it might be worth getting a second opinion from a reputable independent shop in your area if possible?
    I'm sure others here who have experience with this will chime in with better advice.
     
    usmc2msu and Tacoma#5150[OP] like this.
  5. Jul 11, 2025 at 4:38 PM
    #5
    Bishop84

    Bishop84 Well-Known Member

    Joined:
    Dec 17, 2015
    Member:
    #172494
    Messages:
    11,938
    Gender:
    Male
    Its possible they are worn, but I've seen exhaust leaks from the down pipe cause this. Has it ever had any major work done to it?

    Secondly, don't return to that shop. The upsteam primary catalytic converters are monitored for failure, the down stream secondary cats are not.

    They are giving you a f-off quote because they arent sure of their diagnostics.

    I've never called secondary cats for P0420 or P0430, the shop is incompetent.

    [​IMG]

    They should have only quoted the cats that look like #1 in this picture.
     
    usmc2msu and Tacoma#5150[OP] like this.
  6. Jul 11, 2025 at 4:51 PM
    #6
    Tacoma#5150

    Tacoma#5150 [OP] Well-Known Member

    Joined:
    Aug 8, 2020
    Member:
    #337025
    Messages:
    66
    Gender:
    Female
    Vehicle:
    2020 Tacoma Off Road
     
  7. Jul 11, 2025 at 4:51 PM
    #7
    Tacoma#5150

    Tacoma#5150 [OP] Well-Known Member

    Joined:
    Aug 8, 2020
    Member:
    #337025
    Messages:
    66
    Gender:
    Female
    Vehicle:
    2020 Tacoma Off Road
    I finally got the codes from the Service Advisor: P0420, P0430, B15FE, P043000, C1241, C1AC2, B15AD, C1AC1
     
  8. Jul 11, 2025 at 5:03 PM
    #8
    Tacoma#5150

    Tacoma#5150 [OP] Well-Known Member

    Joined:
    Aug 8, 2020
    Member:
    #337025
    Messages:
    66
    Gender:
    Female
    Vehicle:
    2020 Tacoma Off Road
    I really appreciate all the assistance and replies. The price of $6800.00 just rolls off Service Advisor's tongue like everyone has that kind of money. I'm retired and my truck is running great except for the check engine light that came on. It accelerates and is not sluggish. I just came back from a road trip without any mechanical problems except for the check engine light so yes I am shaking my head over this.
     
    Phlogiston and usmc2msu like this.
  9. Jul 11, 2025 at 5:22 PM
    #9
    bigoldbeef

    bigoldbeef Well-Known Member

    Joined:
    Mar 1, 2015
    Member:
    #149863
    Messages:
    572
    Gender:
    Male
    Vehicle:
    18 DCSB OR MT, 22 DCSB OR AUTO
    If your cats are bad, only the front integrated manifold ones are monitored.

    The rears after the o2 sensors aren’t monitored.

    They are less than 2k for both with new hardware and gaskets. I replaced mine in my driveway, 2-3 hour job to do both.
     
    usmc2msu and Phlogiston like this.
  10. Jul 11, 2025 at 6:49 PM
    #10
    kahanabob

    kahanabob Well-Known Member

    Joined:
    Feb 19, 2011
    Member:
    #51477
    Messages:
    2,571
    Gender:
    Male
    Maui
    Vehicle:
    16 TRD 2WD 4DR
    If you clear the check engine does it come back on. Either way if it were me i would forget about it and just drive it.
    Or take it to an independent muffler shop.
     

Products Discussed in

To Top