2001 Prius MCU upgrade to fix P0420

Discussion in 'Generation 1 Prius Discussion' started by czunit, May 28, 2019.

  1. czunit

    czunit Junior Member

    Joined:
    Nov 23, 2011
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    Location:
    baltimore MD
    Vehicle:
    2001 Prius
    Model:
    One
    Hi!

    I (still) have a 2001 Prius which has been throwing P420 errors over the past few years. They seem to coincide with the ethanol fuel mix here in MD, I noticed a similar problem on my 2002 Sienna. Replacing the catalytic converter is an option, however was there a CPU/MCU upgrade for the 2001 Prius in order to handle the ethanol fuel, and any other options aside from swapping the cats?

    Car has about 210k miles, I rebuilt the pack with Gen 2 cells at 150k, recently replaced the plugs (why not), and I will probably keep the car forever.
     
  2. vaughnstark777

    Joined:
    May 4, 2012
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    Location:
    Roy, WA
    Vehicle:
    2001 Prius
    Model:
    I
    I would be interested to know that also.
     
  3. czunit

    czunit Junior Member

    Joined:
    Nov 23, 2011
    27
    14
    0
    Location:
    baltimore MD
    Vehicle:
    2001 Prius
    Model:
    One
    No upgrade apparently however I did replace the 4 COP (coil on plug) units and the car came to green within a day. And just passed emissions. So maybe mediocre COP units can do it.
     
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