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P0304, and no cause found

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by douglasjre, Jan 27, 2019.

  1. douglasjre

    douglasjre Senior Member

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    The engine shutters at 1500 RPMs there's no check engine light lighting up but techstream software reveals a p0304 code. As we know this is a cylinder 4 misfire moving the coil pack from 4 to 3 and the plug from 4 to 2 and the injector from 4 to 1 clearing the codes and retesting it is still reveals the cylinder four misfire and it only happens at 1500 RPMs when the engine is warm not cold. Any knownknown causes? Cylinder compression test 175 PSI for all four cylinders. There is no antifreeze losas andthere'sno oil on the spark plug. And no there isn't any oil in the antifreeze either
     
    #1 douglasjre, Jan 27, 2019
  2. bisco

    bisco cookie crumbler

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    ouch. 2010 with how many miles?
     
    #2 bisco, Jan 27, 2019
  3. mjoo

    mjoo Senior Member

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    Too much carbon in the combustion chamber? EGR distribution problem (intake manifold EGR ports plugged)?

    Pixel XL ?
     
    #3 mjoo, Jan 27, 2019
    m.wynn and Raytheeagle like this.
  4. Raytheeagle

    Raytheeagle Senior Member

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    It’s either fuel or air caused;).

    So if you’ve moved coils around and it still resides in cylinder 4, I’d look at the injector and intake manifold.

    Good luck and keep us posted (y).
     
    #4 Raytheeagle, Jan 27, 2019
    mjoo and m.wynn like this.
  5. douglasjre

    douglasjre Senior Member

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    Screenshots
     

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    #5 douglasjre, Jan 27, 2019
  6. mjoo

    mjoo Senior Member

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    Battery voltage is listed as 12.1V. Isn't that low?

    Pixel XL ?
     
    #6 mjoo, Jan 27, 2019
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