P0420

Discussion in 'Modifications & DIY how-to' started by Dheim96, Jan 8, 2012.

  1. Dheim96

    Dheim96 Member

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    Im driving back from MD with my car and I get off the my exit in GA. As soon as I get off the check engine light comes on and the cruise control light is flashing. I went to autozone and had them pull the code. It's a P0420. Anyone ever run across this? Could be a bad O2 sensor, ignition system or A/F ratio is what they said.
     
    #1 Dheim96, Jan 8, 2012
  2. integroid

    integroid
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    Do you have a catless downpipe?
     
    #2 integroid, Jan 8, 2012
  3. Dheim96

    Dheim96 Member

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    Stock downpipe
     
    #3 Dheim96, Jan 8, 2012
  4. b reel

    b reel Active Member

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    question is do you have an AP or open source tune? The code can be turned off
     
    #4 b reel, Jan 8, 2012
  5. integroid

    integroid
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    yeah but why is it coming up to begin with when he has a stock downpipe. Clear the code and see if it comes back. It might have been a fluke.
     
    #5 integroid, Jan 8, 2012
  6. wagunz_pwn

    wagunz_pwn Active Member

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    Probably a bad O2 sensor.

    You could also try cleaning your maf.
     
    #6 wagunz_pwn, Jan 8, 2012
  7. Dheim96

    Dheim96 Member

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    I don't have either.
     
    #7 Dheim96, Jan 8, 2012
  8. Matt

    Matt Think before you post
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    catalyst inefficiency is typically a bad o2 sensor.
     
    #8 Matt, Jan 8, 2012
  9. GTscoob

    GTscoob Black is Beautiful

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    Most definitely if the rest of the car is stock.
     
    #9 GTscoob, Jan 9, 2012
  10. Dheim96

    Dheim96 Member

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    So, the check engine light went off yesterday. I didn't do anything. works for me.
     
    #10 Dheim96, Jan 12, 2012
  11. integroid

    integroid
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    It will go off after a few hours of driving. I would get it cleared and then see if it comes back on.
     
    #11 integroid, Jan 12, 2012
  12. Dheim96

    Dheim96 Member

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    The weird thing is that the light was on for about 4 days and then just went off yesterday.
     
    #12 Dheim96, Jan 12, 2012
  13. Jake

    Jake Active Member

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    it does that. doesnt mean the O2 magically fixed itself. its still in there.
     
    #13 Jake, Jan 12, 2012
  14. Dheim96

    Dheim96 Member

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    I'll have autozone clear the code and then see what happens.
     
    #14 Dheim96, Jan 12, 2012
  15. CelticPride

    CelticPride Banned

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    o2 doesn't fix itself....it just didn't pop that code again in so many drive cycles.

    If you as much as look at the o2, it'll die on you :|
     
    #15 CelticPride, Jan 12, 2012
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