Gen2 Catalytic replacement P0420 - which section to buy? cat only, front half, entire middle section

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Andrew Vanis, Jul 14, 2018.

  1. Andrew Vanis

    Andrew Vanis Junior Member

    Joined:
    Jul 7, 2018
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    Location:
    Albuquerque
    Vehicle:
    2005 Prius
    Model:
    N/A
    Seems like I can replace just the cat and weld it in $38 generic, $65 magnaflow
    I can replace the front haf of the mid section for $100 - maybe weld?
    I can replace the entire misd section an bolt-on only for $250

    Thinking since I have to weld in 1 or 2 I might as well do 1 its cheeper

    3 seems easier...

    ideas?
     
    #1 Andrew Vanis, Jul 14, 2018
  2. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
    Model:
    Two
    The O2 sensor is located downstream from the first catalytic converter, so the first catalytic converter definitely must be replaced. The second catalytic converter performance is not being monitored by the engine ECU since it is downstream from the O2 sensor; however if that converter is clogged or plugged then it would help to replace that as well.
     
    #2 Patrick Wong, Jul 14, 2018
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