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Engine Racing

Discussion in 'Gen 2 Prius Technical Discussion' started by jsinclair92, Nov 11, 2021.

  1. jsinclair92

    jsinclair92 Junior Member

    Joined:
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    Location:
    Jackson, TN
    Vehicle:
    2008 Prius
    The other day I replaced the speed sensor on the front passenger side due to the light on the dash and a diagnostic check stating it was bad.

    Just my luck, the head of the speed sensor bolt snapped off and I had to tap it and re-thread. Man was that a fun time.

    I needed a little bit more elbow room so I removed the brake caliper, disconnected the battery, since the brakes pad fell out (again, just my luck).

    Since then, my car hasn't ran right. It's revving really high, sounds like it can't get out of its own way. I've driven it a few hundred miles since then, and there is no check engine light.

    What could be the cause of this? I can see disconnecting the battery causing problems, but I assumed those would have cleared up by now.
     
    #1 jsinclair92, Nov 11, 2021
  2. bisco

    bisco cookie crumbler

    Joined:
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    boston
    Vehicle:
    2012 Prius Plug-in
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    Plug-in Base
    does the wheel spin freely?
     
    #2 bisco, Nov 11, 2021
  3. dolj

    dolj Senior Member

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    You don't mention the number of miles on the car, but when was the last time the throttle body and throttle butterfly plate were cleaned? Might be worth inspecting and cleaning if dirty.
     
    #3 dolj, Nov 11, 2021
    SFO likes this.
  4. TheLastMojojomo

    TheLastMojojomo Active Member

    Joined:
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    Location:
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    Vehicle:
    2009 Prius
    Model:
    Touring
    I might have an explanation for this "Engine Racing" you're experiencing. You'll have to describe a bit more in-depth of what your experiencing.

    If by engine racing you mean the engine is always kicking on with little pedal input and the Prius is refusing to use EV mode like it did before at speeds between 0-42mph, See my post here on a low mpg mechanism that results from disconnecting the 12v battery.

    It's a very comprehensive post that details what you may be experiencing.

    Posted via the PriusChat mobile app.
     
    #4 TheLastMojojomo, Nov 12, 2021
    Last edited: Nov 12, 2021
  5. jsinclair92

    jsinclair92 Junior Member

    Joined:
    Mar 24, 2017
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    Location:
    Jackson, TN
    Vehicle:
    2008 Prius
    Last night I found and fixed an exhaust leak, but since it was past the catalytic converter, I guess that's why the car wasn't throwing a code? I haven't driven it yet to determine if this resolved my issue, but the car definitely sounded much quieter just idling in the garage.

    I haven't checked to see if the wheel turns freely, and I don't recall the last time I cleaned the TB, indications that it's time to take care of both of those this morning.

    One last question though, after replacing the speed sensor, I used the paperclip in OBD2 port method to clear the light on the dash, but wasn't able to get the light to go off. Has anyone else had similar trouble and if so, were you able to get the light to go off? I have a feeling I'd be opening up a can of worms by delving too deeply into the ABS system, but was just curious.
     
    #5 jsinclair92, Nov 13, 2021
  6. dolj

    dolj Senior Member

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    It is likely that the codes are clearing (presuming you're doing it correctly) and then immediately setting. Rather than just blindly trying to clear the codes, use the same paperclip technique to get the blink codes. That should give you a good steer as to what's going on. You can see the lights blinking steadily which indicates no codes at ~2:24 in that video. You count the blinks on each light that is not doing that steady blink to get two-digit codes. Search for older posts here by ChapmanF to get more details if you can't work it out.
     
    #6 dolj, Nov 13, 2021
    Last edited: Nov 13, 2021
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