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P0301 After Head Gasket Replacement

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by TwoPriusInTenn, Jan 2, 2021.

  1. TwoPriusInTenn

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    I replaced the headgasket on my daughter's 2012 Prius Two. Following the 6 -7 "test drives" I've taken it continues to register the P0301. I have replaced spark plugs, coils, cleaned the injectors and replaced the pcv valve.

    Could there be a problem with the ecu? Does it need to be reset? I'm at a loss as to what it could be.
     
  2. The Critic

    The Critic Resident Critic

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    Do a compression test. Perhaps you have a slightly bent rod from the coolant ingestion. Slightly bent rod may cause the piston to not reach the deck, resulting in lower compression in that cylinder. Inadequate compression will cause a misfire.
     
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  3. TwoPriusInTenn

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    Thank you. I will do a compression test using my TechStream.
     
  4. The Critic

    The Critic Resident Critic

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    Tech stream will do a relative compression test. Not as good as a real one, but it may suffice.
     
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  5. Mendel Leisk

    Mendel Leisk Senior Member

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    Was wondering about that.
     
  6. TwoPriusInTenn

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    Based on a little more research, it appears to be a bent rod in cylinder one. We are currently opting for an engine swap.

    Anyone know of a good step by step video on how this is done?
    My main concern is lining up the engine and the trans.
     
  7. Mendel Leisk

    Mendel Leisk Senior Member

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    Check out @Ragingfit fits videos “fix that Prius” is his channel I think. Believe they’re linked in Prius v mod forum, pinned. Don’t let loc throw you off.
     
  8. TwoPriusInTenn

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    Thank you. I will check that out.
     
  9. TwoPriusInTenn

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    I wanted to provide an end result to these posts. Turned out to be a bent rod in cylinder one. My daughter decided to sell the car as opposed to replacing the engine.

    Thank you for your input and assistance.
     
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  10. Mendel Leisk

    Mendel Leisk Senior Member

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    Cylinder one turns up regular as rain. And Cylinder one Exhaust Gas Recirculation passage in the intake is first to clog, regular as rain.
     
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