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multiple emissions cel issues

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by wrbari, Apr 10, 2017.

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  1. wrbari

    wrbari New Member

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    Hi there! Looking to get some help figuring out what exactly is going on with my '10 prius. Has a little over 200k mileage, and had a check engine code p0401-egr valve. I removed the pipe connected to the valve and cleaned, had a lot of carbon buildup in it. After this the code went away, but today after driving, got four new emissions based codes...

    codes are
    P0102
    P0031
    P0141 and
    P0403.

    Could these really all be inter-related? Or is it more likely that my ecm module is on the fritz? Car seems to be running fine as best as I can tell.
     
  2. bisco

    bisco cookie crumbler

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    welcome!
    did you replace the egr valve?
     
  3. wrbari

    wrbari New Member

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    we did not replace the egr valve. Just cleaned the metal pipe with the carbon buildup, then waited to see if engine code would resolve itself.
     
  4. tankyuong

    tankyuong Senior Member

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    i would take the egr valve off and flush it out with brake cleaner
     
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  5. Raytheeagle

    Raytheeagle Senior Member

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    What maintenance has been done on your Prius with 200 k miles? Does it consume any oil? Have you cleaned the intake manifold?
     
  6. wrbari

    wrbari New Member

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    Routine maintenance mostly, the thing has not had much need for a shop. To the best of my knowledge it does not really consume oil, though I would imagine it will start that before long. And no, have not touched the intake manifold yet, up until the check engine lights car had seemed to be running fine.
     
  7. Rebound

    Rebound Senior Member

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    When you cleaned that pipe, how much carbon build-up was present? Was it a thin, hard layer, or was it a thick, oily gooey mess that clogged a substantial part of the pipe?
     
  8. B Baker

    B Baker New Member

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    Reading this thread and it sounds similar to our current issue with a 2010 Prius 3. We have 3 codes P0031, P0102 and P0403.
    Took to our local garage and then said that the 3 sensors are on the same fuse. They found the fuse was blown. They replaced the fuse, cleared the codes and took for a test drive. In about 1 mile of driving the codes came back, the fuse was blown again. Did the same thing once more, replacing fuse with the same outcome. Garage said that there appears to be a short somewhere causing this issue and directed us to the dealer for further troubleshooting. I did also try cleaning the MAF Sensor previously. Might the Air Flow Sensor be causing the Short?
     
  9. bisco

    bisco cookie crumbler

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    how many miles on her, did you clean the egr circuit?
     
  10. B Baker

    B Baker New Member

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    It has approx 165,000 miles. Took it to the Dealer yesterday and they found that one of the O2 Sensor wiring was causing the Short, as it was hanging very close or against the Heatshield. They replaced the O2 Sensor and secured the wiring away from the Heatshield and it only cost $500, LOL, but not laughing.
     
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  11. bisco

    bisco cookie crumbler

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    ouch!
    at least she's up and running (y)