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exhaust smell in cabin

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by priusmanneedhelp, May 21, 2022.

  1. priusmanneedhelp

    priusmanneedhelp Junior Member

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    Hello. Previous owners replaced the cat and welded it on poorly. Left an exhaust leak that I later fixed to pass emissions. The smell still remains in the cabin and I still have the p0420 code.

    Can a bad cat cause an exhaust smell to leak into cabin?

    Ive checked all up and down the exhaust system and I find no leaks. None at the manifold either.

    Is it time to bite the bullet and get a new cat?

    P.S I have also replaced the oxygen sensor just to be sure but the issue remains.

    thanks
     
    #1 priusmanneedhelp, May 21, 2022
  2. JC91006

    JC91006 Senior Member

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    There should never be exhaust smell in the car, that's kinda dangerous. How did you pass emissions with p0420? That should give you a check engine light
     
    #2 JC91006, May 21, 2022
  3. priusmanneedhelp

    priusmanneedhelp Junior Member

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    Sorry if I worded that weird but I'm trying to pass emissions right now. Def have a check engine light. Its a slight exhaust smell when Im driving. seems to go away when the heater is on. The smell lessened when I repaired the exhaust leak on the poor weld.

    Would a bad cat cause this smell in the cabin?
     
    #3 priusmanneedhelp, May 21, 2022
  4. JC91006

    JC91006 Senior Member

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    A bad weld would only make the exhaust really loud, the gases should not get into the cabin.
     
    #4 JC91006, May 21, 2022
  5. priusmanneedhelp

    priusmanneedhelp Junior Member

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    wasn't ever really loud. Wasn't a huge leak but was def leaking when I did the soapy water test. Fixed it with one of those jb weld exhaust tapes. What would cause exhaust smell in the cabin?
     
    #5 priusmanneedhelp, May 21, 2022
  6. JC91006

    JC91006 Senior Member

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    I don't know how exhaust can get inside the car, maybe if the mixture was too rich. The oxygen sensor is oem right?? Denso? I've bought cheap aftermarket Catalytic converters, not all of them work. You'll still get a check engine light from the cheap replacements.
     
    #6 JC91006, May 22, 2022
  7. priusmanneedhelp

    priusmanneedhelp Junior Member

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    yup oem denso.
     
    #7 priusmanneedhelp, May 22, 2022
  8. bisco

    bisco cookie crumbler

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    could it be in the engine bay, and coming in through hvac?
     
    #8 bisco, May 22, 2022
  9. pasadena_commut

    pasadena_commut Senior Member

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    The previous owners replaced it because why? Stolen? Sometimes the thieves are not very bright and make cuts in the wrong places. Maybe not even all the way through a pipe, just through the wall. Treat it like any other exhaust leak problem. With the car up on jacks spray along the exhaust with soap water while a helper blows air into the tailpipe with a leaf blower, and like for bubbles.

    For whatever its worth, my son's POS RV had these issues and it was leaking at every junction where two pipes were joined with a gasket and some bolts. It was also leaking at the exhaust manifold due to multiple broken bolts there.
     
    #9 pasadena_commut, May 22, 2022
  10. edthefox5

    edthefox5 Senior Member

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    You probably either have the wrong donut inthe header connection or you reused the oem donut and it’s damaged.

    Take it to a muffler shop.
     
    #10 edthefox5, May 28, 2022
    tangerino likes this.
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