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2006 HyHi CEL P0300, 301, 302 and 306

Discussion in 'Gen II Prius Care, Maintenance and Troubleshooting' started by White Gold Prius, Jan 10, 2012.

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  1. White Gold Prius

    White Gold Prius Junior Member

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    Your Vehicle Year:
    Other Hybrid
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    I just came back form a vacation. Drove my 2006 HyHi from Houston to Miami and back for the second time this year (last time in August without any problems).

    200 miles from the start, CEL came on. Went to the local Autozone and got P0300, 301, 302 and 306 readings.

    I had the same readings in
    01/2010 (got cleared by Toyota)
    11/2010 (changed spark plugs and cleared by Toyota) and now again in 12/2011.

    What is going on? The same issue every year around the same time (winter? colder temperatures?)

    I took to a local mechanic along the hwy 10 (luckily we worked at Toyota for 30 years). He did some scans and told me that everything is OK, suggested to use Fuel Injector cleaner for a few cycles. So I did until I got to Miami. Just FYI, I NEVER noticed any performance problems and/or noises coming from the engine.

    So I got to Miami, cleared the CEL and drove around fine until I got back on highway heading home. As soon I accelerated to 80 mph, the CEL went on and stayed on. Then every time I went to 80mph, it would start flashing and then went steady when I slow down.

    Any ideas, PLEASE? Thanks.
  2. seilerts

    seilerts Battery Curmudgeon

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    Try cleaning the MAF sensor. Misfire at high speed/load is potentially an air metering problem (too lean).
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  3. Patrick Wong

    Patrick Wong DIY Enthusiast

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    MAF sensor cleaning is an easy item to do. If you still have the problem after that, I suggest that you have the fuel line pressure checked. Since the misfire DTC is only logged at 80 mph (which implies a fairly fast engine RPM speed and a high rate of fuel consumption) maybe fuel line pressure is marginally low but this does not manifest itself except at high rates of fuel consumption.
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  4. White Gold Prius

    White Gold Prius Junior Member

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    Thanks for your replies. If those are the only reasons I get CEL, why doesn't it come out at other times when I drive over 80mph? It seems to come out at certain intervals. Could it be bad gas or fuel injectors?

    I will take it to a local Toyota for a free diagnostics. Also, any news on the latest inverter recall? When will they start replacing them? I have not gotten a promised call from my dealer yet?
  5. White Gold Prius

    White Gold Prius Junior Member

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    To my surprise, it turned out to be a blown passenger side strut. I actually do remember how I may have blown it (flying over rail road tracks).

    Should I get and OEM strut assembly or aftermarket? replace both drivers and passengers? Thanks.
  6. seilerts

    seilerts Battery Curmudgeon

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    Huh? How can a blown strut cause misfire?

    Anyway, do replace both sides.
  7. White Gold Prius

    White Gold Prius Junior Member

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    Sorry for bumping an old post but I think it's interesting. My 2006 HiHy has the same problem coming up every year though everytime I get it fixed somehow.

    P0300, 301, 302

    01/2010 (just got cleared by Toyota)
    11/2010 (changed spark plugs and cleared by Toyota)
    12/2011 (changed front passenger side strut)
    04/2013 !!!

    Note:
    1) no noticeable change in performance or anything
    2) after the code is cleared it takes almost a year to come up again
    3) always comes up during highway driving and registers misfires by blinking CEL

    Please help !!!
  8. nh7o

    nh7o Off grid since 1980

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    Try swapping the igniters from cyl 1,2 with cyl 3,4. I guess you might have to wait a year to see if you get P0303 and P0304. Also, how is the oil consumption per year?
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