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2009 Prius CEL P0303 help.

Discussion in 'Gen 2 Prius Main Forum' started by Kaptainkid1, May 28, 2020.

  1. Kaptainkid1

    Kaptainkid1 Active Member

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    Vehicle:
    2009 Prius
    Model:
    III
    I pulled the CEL code and code reader spits out P0303 cylinder 3 misfire.
    History : At 160k I changed the spark plugs with OEM toyota plug.
    2009 Prius
    180k
    Drive really rough and check engine light is on.

    Clear code and pulled off #3 ignition coil and switch it with #2 coil. Ran car around the block and noticed ODBII reader and another check engine light P0303 again. Car still running rough and checked the forum and found out could be #3 injectors.
    Going to buy a set of new injectors but wanted the forum's opinion could this be the problem?


    SM-J737T1 ?
     
  2. Skibob

    Skibob Senior Member

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    Where did you buy the plugs from and what brand are they? There have been reports of fake NGK plugs being sold on E-Bay.
     
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  3. SFO

    SFO Senior Member

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  4. Kaptainkid1

    Kaptainkid1 Active Member

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    III
    I fixed the problem by troubling shooting all the possible out comes. I swapped the coils drove around the block and got P0303 error code.
    I swapped Injectors and drove around the block and P0303 error code again.
    I read long ago that ebay has sellers who sold fake NGK plugs and decided to pull the plugs out. Even though I only drove 20,000 miles on them. Yup the plugs gaps we're way out of spec. 1.4mm. Man I was pissed off. I keep my old plugs and clean them up. Put the old one back in and now I have 4 fake plugs. People beware of fake parts! It's hard to spot. These even came in Toyota Genuine Parts box. See in photos.

    How to spot a fake:



    20200528_183042.jpg 20200528_183017.jpg 20200528_180050.jpg 20200528_173230.jpg

    SM-J737T1 ?
     
  5. Kaptainkid1

    Kaptainkid1 Active Member

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    Location:
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    2009 Prius
    Model:
    III
    Here is how to spot a fake Denso plug.





    SM-J737T1 ?
     
  6. Skibob

    Skibob Senior Member

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    I never go with Denso plugs. Why run with the second string when you can go with the varsity team (NGK)
     
  7. dolj

    dolj Senior Member

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    DENSO Corporation is a well-established spin-off of Toyota Motor Corporation (TMC), it is Japan's leading producer of automobile components and the world's fourth largest. As the second-largest member of the Toyota Group, more than half of DENSO's products go to Toyota Motor Corporation (TMC), which owns better than 20 percent of DENSO stock.

    Considering this, I would have thought DENSO plugs would be the plug of choice for a Toyota, not second string.
     
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