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Misfire continues

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Theman414, Mar 2, 2019.

  1. Theman414

    Theman414 Junior Member

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    Okay so work done so far, all injectors changed, coils swapped with no change, spark plugs changed, entire intake system cleaned, compression check, coolant system pressure test, fuel pressure test, 12V battery changed. Now the car is still throwing P0301, P0304, and P0300. Now what did change that I noticed was I put the car in Drive and the idle sped up quite a bit before leveling out. Going down the road if it starts to misfire I can put the gas to the floor and it stops. It’s only when I turn right or at the low end of the RPM’s. What am I missing please help
     
  2. orenji

    orenji Senior Member

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    You cleaned the intake, does that mean the EGR cooler as well?
     
  3. Raytheeagle

    Raytheeagle Senior Member

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    Is the coolant level stable?
     
  4. Muneeb

    Muneeb Junior Member

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    Sounds like a EGR valve, better to clean the EGR Valve and EGR Cooler and this should resolve the issue. If problem persist try changing the EGR Valve. As you have done lot of work its better to put the new EGR Valve and clean the EGR Cooler and pipe.
     
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  5. Granny hill hot rods

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    I have the same issue misfire on cyl 3 ,change the plugs and coil packs all 4 not bad looking for 226000 miles,,still did it ,so changed the egr valve new toyota part,cleaned the intake tube ,but didn't clean the egr intercooler like a big dummy so pull all back apart it is completely stopped up solvent will not even run through it ,so letting it soak over night
    ,just wondering how far back the system must I go I cleaned the tube that intercooler attached to ,maybe this will work ,btw only time it misfired is pulling a hill around 70mph,
     
  6. Mendel Leisk

    Mendel Leisk Senior Member

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    How many miles on it?
     
  7. Granny hill hot rods

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  8. Granny hill hot rods

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    226000
     
  9. tankyuong

    tankyuong Senior Member

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    Blown head gasket
     
  10. Granny hill hot rods

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    Not running hot ,not losing coolant idk might be thanks
    Only misfired for a few seconds then runs fine the check engine light flashes I let off the gas it starts running great again?
     
  11. Mendel Leisk

    Mendel Leisk Senior Member

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    And clogged or near-clogged EGR cooler.
     
  12. Raytheeagle

    Raytheeagle Senior Member

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    Welcome to Prius Chat (y).

    Once you get the cooler, that’s the extent of the plugging ;).

    Use a pressure washer and it’ll get the deposits right out:).

    Good luck and keep us posted (y).
     
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  13. Mendel Leisk

    Mendel Leisk Senior Member

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    Oxi-Clean solution soaks, if you want to take the slow road. About half a dozen, hour long soaks, and run a thin wire through if needed to get it through.
     
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  14. Raytheeagle

    Raytheeagle Senior Member

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    I bought a tub of the stuff and it just never cuts through a cooler that is packed:cool:.

    But 1700 psi does ;).

    Just did my 10th cleanse a couple of weekends back when the Bay Area meetup was in town:).

    3 at once in under 15 minutes they were clean and ready for service(y).
     
  15. Mendel Leisk

    Mendel Leisk Senior Member

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    Yeah I think it depends on degree of clogging.

    That sounds better than ultrasonic cleaning, and morereadily available.

    Different horses for different courses: if you're like me, clean the EGR on a whim, at 50K miles lol, Oxi-Clean gets you were you want to go (John Candy quote).
     
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  16. Raytheeagle

    Raytheeagle Senior Member

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    For the above, pressure is the solution;).

    I soaked one for a couple of weeks with hot Oxi clean and ended up giving up and hitting it with the pressure washer:).

    The setup is the most time consuming part, so if you don’t have one, use the local self serve car wash and theirs will do just fine(y).
     
  17. Granny hill hot rods

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    You were correct clogged EGR cooler ticket to the carwash cleaned it out installed everything back 600 miles so far issue solved thanks
     
  18. Raytheeagle

    Raytheeagle Senior Member

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    Maybe if enough people do the pressure washing routine @Mendel Leisk will give up the Oxi Clean for the next round:).

    I guess if there will ever be a next round that is(y).
     
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  19. padroo

    padroo Senior Member

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    When you put the gas pedal to the floor WOT, the ECM goes full rich and takes no information from the O2 sensor, check it out.

    You need to get hooked up to a scan tool and check your O2 sensors.

    I didn't see the MAF sensor cleaning on the list?
     
  20. Granny hill hot rods

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    Update on misfire 3 cylinder EGR valve intercooler was completely stopped up took it to the car wash pressure washed it cleaned it out installed everything back 600 Mi no misfire I believe the issue is solved thanks for all the help
     
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