2007 Prius - Misfire Cylinder 1

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by KitsuneVoss, Dec 18, 2024.

  1. KitsuneVoss

    KitsuneVoss Member

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    My roommate's Prius, a 2007, had a misfire on cylinder 1. Over the last week, I replaced both all of the spark plugs and the coils and cleared the code. Still misfiring after replacing all of them. Same place, cylinder 1, so does not appear to be anything I have done.

    Anything else which could be a common cause?
    Also cylinder 1 is the cylinder closest to the passenger side?
     
    #1 KitsuneVoss, Dec 18, 2024
  2. rjparker

    rjparker Tu Humilde Sirviente

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    #2 rjparker, Dec 19, 2024
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  3. pasadena_commut

    pasadena_commut Senior Member

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    Replaced the coils with what brand, from where? Aftermarket coils can be DOA, "OEM" ones from Amazon or Ebay can be fakes. Ditto for the plugs. That said, there is only a 25% chance that a bad component would end up on the same cylinder. So I agree with the previous post, a bad injector is the next thing to consider. After that check the wires to the injector and coil pack.

    However...

    Better to start by swapping parts between two cylinders. If the problem moves with the part you have found the problem - only then buy a replacement. Replacing the plugs with new ones is a small enough expense that there is no harm in doing that, as along as you are confident the plugs are the right type from a reliable source. Coils and injectors are more expensive, better to prove one is bad before replacing it.
     
    #3 pasadena_commut, Dec 19, 2024
  4. KitsuneVoss

    KitsuneVoss Member

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    While the injectors can be expensive, doesn't look that hard to replace them from watching videos when it comes down to it.
    Likely wait until my own vehicle situation is solved so that that we have a backup however

    Try a fuel injector cleaner because cheap and easy in the meantime
     
    #4 KitsuneVoss, Dec 19, 2024
  5. rjparker

    rjparker Tu Humilde Sirviente

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    From yesterday
     
    #5 rjparker, Dec 19, 2024
  6. KitsuneVoss

    KitsuneVoss Member

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    Um, I suspect just getting new injectors is cheaper than putting them through the bath due to the cost of the bath machine
     
    #6 KitsuneVoss, Dec 19, 2024
  7. KitsuneVoss

    KitsuneVoss Member

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    I am pretty sure that spark plugs are good because they are Denco from O'Reilly's but I can easily switch coils between 1 and 2 as a quick test. Be a few days, Friday or Saturday, but still not a big job.
     
    #7 KitsuneVoss, Dec 19, 2024
  8. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    consider a rebuild service for the injectors. It's much cheaper than OE replacements, and a rebuilt Toyota injector works very well compared to "discount aftermarket."

    The downside is car downtime while waiting for the injectors to be mailed there and back.
     
    #8 Leadfoot J. McCoalroller, Dec 19, 2024
  9. Hayslayer

    Hayslayer Junior Member

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    Hopefully that's not the Chinese version of Denso :D
     
    #9 Hayslayer, Dec 19, 2024
  10. KitsuneVoss

    KitsuneVoss Member

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    Well, nobody said I could spell

    You can buy remanufactured / refurbished Denso fuel injectors. Should I just purchase them if neither flipping the coils or running a fuel injector cleaner helps? They look like they are a little bit more than "Discount Aftermarket" but nothing like new as far as price.
     
    #10 KitsuneVoss, Dec 19, 2024
  11. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    You might be on to something there. That option didn't exist the last time I had needs, so I paid the $25-30 per injector and the shipping and did it that way.

    So I know an OEM injector can be rebuilt to proper standards, I just don't know if those particular rebuilders are doing it right.
     
    #11 Leadfoot J. McCoalroller, Dec 19, 2024
  12. Hayslayer

    Hayslayer Junior Member

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    You're right about the injectors. I was looking at new ones a year or so ago, and seem to remember RockAuto.com offered the rebuilt OEM injectors at a pretty fair price.
     
    #12 Hayslayer, Dec 19, 2024
    Last edited: Dec 19, 2024
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