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Aftermarket cat.

Discussion in 'Gen 2 Prius Main Forum' started by lexidium, Apr 16, 2024.

  1. lexidium

    lexidium Active Member

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    It was throwing a p0240 code so had an aftermarket cat fitted and that seemed to cure it.
    Now the exhaust rattles like a pig for the first few minutes after setting off and then completely stops.
    I'm assuming it's when it gets hot that it swells up or something and it stops rattling.
    All the joints etc are ok and it's not catching on anything.
    Can a faulty cat do this?
     
    Data Daedalus likes this.
  2. dolj

    dolj Senior Member

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    Was the doughnut gasket at the exhaust manifold replaced with a new Toyota OEM one?
     
  3. lexidium

    lexidium Active Member

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    Not toyota I don't think.
    But none of the exhaust is Toyota any more.
     
    #3 lexidium, Apr 16, 2024
    Last edited: Apr 16, 2024
  4. Tombukt2

    Tombukt2 Senior Member

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    So you have to get under the car with a rubber hammer and tap and bang until you get the rattle to happen cold while you're under there and see what it is usually it's not the brick inside of the bulbous part of the metal where the brick is usually that's in there pretty good heat's not going to make that really bounce around per se usually it is a shield bracket that sort of thing that heats up a little and then it doesn't move around My '09 does the same thing and it is in fact just the way the metal is assembled there's a long run between what used to be the converter and the cat back pipe I am in a city and township that has no emissions so on this car the catalytic converter is literally gone and a straight pipe is there to make up for the missing connection
     
  5. dolj

    dolj Senior Member

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    If the A/M part came with a new doughnut gasket, it is usually junk. Reuse the original Toyota gasket or get a new Toyota gasket if the old one is not reusable.
     
  6. lexidium

    lexidium Active Member

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    Will give it a try.
    Thank you
     
  7. lexidium

    lexidium Active Member

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    New Toyota donut gasket fitted and it's OK now.
    It's hard to believe that such a small thing can make so much difference.
    Thanks guys.
     
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  8. Ozzbo

    Ozzbo New Member

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    what is the OEM number of that doughnut gasket?
    I have the aftermarket cat, the Denso O2 sensor. But still sometimes I have p0420 error. Could that be due to the doughnut gasket?
     
  9. Tombukt2

    Tombukt2 Senior Member

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    If it's the donut gasket you will hear it It's like a flaw flaw flaw sound air escaping past this big round conical asbestos material looking ring with metal on it. The aftermarket ones can work and if you go to a Midas muffler shop they'll sell you one that's a little oversized on purpose so that when you draw up against it what you're touching is substantial The thin thing that comes with the aftermarket cat they are known to leak The factory one even used is fine You can grab one over at LKQ everybody that's jerk the cats out lets them fall right on the ground they're laying under the car You probably won't have to do anything but reach your hand out and grab it and that's that or shoot around the Midas or ye old local muffler shop and tell him it's a Toyota whatever and he'll show you a rack full of them and grab a certain number and if you had your other cat with you or out you can hold it up to the cat and see that there's plenty big enough to seal and fit and draw up without being all inside the fitting and you're good to go.
     
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  10. lexidium

    lexidium Active Member

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    Ozbo
    My gasket fault was after the the cat was changed (which fixed the P0240)
     
  11. dolj

    dolj Senior Member

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    PNC 17410B - EXHAUST PIPE GASKET
    Part Number 17451-21060
     
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  12. lexidium

    lexidium Active Member

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    gasket.jpg This is the one I got in the UK:
     
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  13. Tombukt2

    Tombukt2 Senior Member

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    Yep they'll be different part numbers throughout the world just because everybody's got to have their individuality in their business That's why there's Toyota motor sales USA Toyota motor sales UK etc etc everybody wants their 5 minutes of fame