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  1. Brian Adcock

    Brian Adcock Junior Member

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    I replaced my plugs, PCB valve, cleaned MAF sensor and throttle body today.

    Afterwards I took it for a spin. The triangle of death warning came on. I went to O'Reilly's and had it scanned. He said misfires on 3 and 4. He cleared the codes and says if they come back that I should replace the coils.

    So far no codes. I attached a photo of the old plugs. The previous owner had the wrong plugs. I researched and found that Denso SK16R11 is the correct plugs. That is what I installed.

    What do you all think? True misfires? Correct plugs? It was my first time doing some preemptive maintenance.


    Brian in central NC
     

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  2. TMR-JWAP

    TMR-JWAP Senior Member

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    Yes, the SK16R11 plugs are correct for the gen 2. There's always equivalents available, tho.

    That being said, I always use the R11s and they have been flawless. The only concern would be where you purchased them and whether they are chinese counterfeits or actual DENSOs. Amazon and eBay are flooded with counterfeits and are lucky to get 20k miles, much less the OEM rated 120k.
     
  3. Brian Adcock

    Brian Adcock Junior Member

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    How can you tell a counterfeit?

    The plugs Installed said Denso SK16R11.


    Think my warning light was from disturbing the undisturbed?
     
  4. ColoradoBoo

    ColoradoBoo Senior Member

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    Hard to say...I assume you disconnected the negative battery terminal on your 12-volt battery before the job? (You would need to since cleaning out the throttle body requires the on-board computer to recalibrate the settings for the internal air flow.)
     
  5. Brian Adcock

    Brian Adcock Junior Member

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    Learning a lot here. I did not disconnect my 12 volt. I suppose this is why I received the misfire codes since the computer had to recalibrate the works.

    I have driven it this afternoon and evening no lights since O'Reilly's cleared the codes for me.


    Thanks so much for your insights and knowledge.

    Brian
     
  6. bisco

    bisco cookie crumbler

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    you can't identify counterfeits. if the codes come back, replace them from a dealer.
     
  7. ChapmanF

    ChapmanF Senior Member

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    Some of the spark-plug makers do offer guides and photos for spotting counterfeits of their plugs ... differences in finish or fonts or spacing and the like.

    Of course, the counterfeiters also study those guides when the legitimate manufacturers put them out.

    But then, the counterfeiters are out to make product for the least possible money, so there's only so far they go to get everything looking right.
     
  8. Brian Adcock

    Brian Adcock Junior Member

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    So far so good gentlemen. I will keep my eyes on it. Thanks again for your insights.
    It's my first Prius and I am enjoying it.

    Brian
     
  9. mr_guy_mann

    mr_guy_mann Senior Member

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    Where did you buy your spark plugs from? If it was from the internet (esp amazon or eBay), then chances are pretty good they are counterfeit.
    (those old plugs were HUGELY worn out). What prompted you to replace them? Could also be that the coils are on the way out.

    I only use Denso - OE coils & NGK or Denso plugs from a reputable source (dealer, brick and mortar supply house, maybe rock-auto).

    Misfires should "only" set P030x codes with the "check engine" light (P0303 & P0304 in this case). - Unless the engine ran so bad that the hybrid vehicle control ecu set an "engine failed to start" code. Don't know since O'Reilly's scantool doesn't have the capability to read codes from most systems on a Gen2 Prius.

    There is nothing to "reset" after replacing ignition parts. If your parts are good, then that should not have caused your problems.

    At some point I would clean the throttle body bore and the MAF sensor. (Use the search function in the Gen2 forums to learn more).

    Posted via the PriusChat mobile app.
     
  10. Brian Adcock

    Brian Adcock Junior Member

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    Hi Mr Guy...

    I purchased from Amazon. I knew it would stumble some from the throttle body cleaning. But it did start on the 3rd try and then the CEL and Triangle came on. The O'Reilly's guy didn't show me his display and I didn't ask to see it. After he reset things my lights have not come back on. I have driven almost 200 miles since that this week.

    I am planning on changing my serpentine belt later today. Yes the old plugs were worn out for sure.

    Source for your plugs and coils???