1. Attachments are working again! Check out this thread for more details and to report any other bugs.

P0420 code after....

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by douglasjre, Sep 14, 2020.

  1. douglasjre

    douglasjre Senior Member

    Joined:
    Sep 13, 2008
    1,773
    617
    0
    Location:
    Orlando, FL
    Vehicle:
    2010 Prius
    Model:
    ----USA----
    Put in a new $99 ebay cat. Same codecoming up again. Advice? (And don't say clear the codes)
     
  2. Kenny94945

    Kenny94945 Active Member

    Joined:
    Mar 24, 2016
    769
    394
    0
    Location:
    Sausalito
    Vehicle:
    2016 Prius v wagon
    Model:
    Four
    You got code 0420 and replaced a cat?
    Did you test the O2 sensor first?
    Did you inspect the wiring and connector to the 02 sensor?

    If all is functioning correctly, and if the new cat is higher flow than OEM, then an 02 sensor extender may keep the code from resetting.

    Good luck.
     
  3. douglasjre

    douglasjre Senior Member

    Joined:
    Sep 13, 2008
    1,773
    617
    0
    Location:
    Orlando, FL
    Vehicle:
    2010 Prius
    Model:
    ----USA----
    PXL_20200915_004829326.jpg PXL_20200915_004841206.jpg PXL_20200915_004852849.jpg PXL_20200915_004904899.jpg I did test the sensors. Here's the data I'm getting on a handheld. I'll pull it up and techstream again tomorrow