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can P0446 cause P0420?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by k1ngn0thing, Jun 26, 2021.

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  1. k1ngn0thing

    k1ngn0thing Member

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    Car's had P0420 for a while, and recently noticed P0446, and I'm wondering if it was there before and I may have missed it. Can an evap issue also cause P0420? So far I've replaced the downstream O2 sensor, which didn't resolve 0420. Also have an upstream and cat replacement but don't want to do any of that yet if there's a chance 0420 can be related to 0446.
     
  2. PriusCamper

    PriusCamper Senior Member

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    Yea... That's the biggest problem with living with a warning light on... You'll never know when/circumstances of when the next warning light comes.

    Good news is an aftermarket replacement cat is less than $200 and if you still have your original cat that's failing, the precious metals inside it can be sold for as much as $1800. So you're actually leaving money on the table by not dealing with your P0420 code.
     
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  3. k1ngn0thing

    k1ngn0thing Member

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    I really don't understand how it's worth that much in scrap. wow, thanks for letting me know. now I'm definitely replacing it.
     
  4. ChapmanF

    ChapmanF Senior Member

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    No obvious causative link between the two occurs to me.
     
  5. k1ngn0thing

    k1ngn0thing Member

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    checked with torque and it does appear to be the cat.
    [​IMG]
     
  6. ChapmanF

    ChapmanF Senior Member

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    Well, to some extent that's a tautology: P0420 is your notification that $21:$a9 didn't pass, it's not as if they're separate pieces of corroborating evidence.

    I'll still stick with my story that I don't see any clear way for your catalyst result to be a consequence of the evap code you mentioned.

    I'm not totally clear on Torque's color coding; I think I've guessed what green and red mean, but what does it mean that $3d:$c8 is black?
     
  7. Avi's Advanced Automotive

    Avi's Advanced Automotive Independent hybrid repair shop

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    Black means it hasn't run that monitor yet.

    I agree the EVAP problem won't cause a P0420.

    Posted via the PriusChat mobile app.
     
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  8. PriusCamper

    PriusCamper Senior Member

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    Rhodium is up near $700 a gram... And it has 2 grams of Rhodium... It also has a couple grams each of Palladium and platinum which are valuable too... Make sure you don't sell it to someone who is paying thieves to steal them.
     
  9. k1ngn0thing

    k1ngn0thing Member

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    so these aftermarket cats must have very little of the stuff, or do they use something else? how many miles can one expect out of an aftermarket?
     
  10. PriusCamper

    PriusCamper Senior Member

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    Decades have gone by since these over-engineered cats were made... These days the ones they make use far less Rhodium. Though you'll likely have more air pollution coming out of your exhaust pipe with them. But then again because your cat is no longer working properly it might be cleaner than what you got. And if you lived in California you wouldn't be allowed to use and aftermarket cat and would have to spend $3-4K on OEM cat.
     
  11. mr_guy_mann

    mr_guy_mann Senior Member

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    The amount of functional time can vary, depending on the quality of the replacement and the condition of the car it goes into. Some have had several years with no problems while others have a P0420 return after a few months. How much oil an engine burns is a consideration (more oil burned usually = faster cat code).

    If I remember correctly, an OE cat has to last (is warranteed for) at least 100 thousand miles (might be up to 150k), while an aftermarket only has to be functional for 25 thousand (maybe 50?).

    Posted via the PriusChat mobile app.
     
    #11 mr_guy_mann, Jun 28, 2021
    Last edited: Jun 28, 2021
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