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Annoying revving sound

Discussion in 'Gen 2 Prius Main Forum' started by mikepaul, Nov 22, 2004.

  1. mikepaul

    mikepaul Senior Member

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    I hadn't run into this before, so I'll ask.

    I was driving Sunday using the pedal and not cruise, and when I pulled my foot off the pedal the engine revved like the car had gone to Neutral and the pedal was still down. Nothing had prevented the pedal from coming back up. It only lasted a few seconds. It hasn't repeated. Yet.

    Annoying throttle-by-wire glitch, or sign of developing trouble in either the throttle or the transmission?...
     
    #1 mikepaul, Nov 22, 2004
  2. john1701a

    john1701a Prius Guru

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    Did the car begin to slow down as requested?

    If so, you have simply experienced your first emissions purge.

    So far (24,562 miles), I have only experienced 2. Both were during the cold season while the system was still warming up. It's part of the design to deal with collected pollutants.
     
    #2 john1701a, Nov 22, 2004
  3. mikepaul

    mikepaul Senior Member

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    OK, it did slow down.

    And it wasn't all that warm out.

    Thanks...
     
    #3 mikepaul, Nov 22, 2004
  4. Sufferin' Prius Envy

    Sufferin' Prius Envy Platinum Member

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    <div class='quotetop'>QUOTE(john1701a\";p=\"52100)</div>
    O.K. I'll bite.
    What is an "emissions purge"?
    [The semi-technical version . . . not the "car-fart" version.]
     
    #4 Sufferin' Prius Envy, Nov 22, 2004
  5. john1701a

    john1701a Prius Guru

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    An "emissions purge" is when certains pollutants, which cannot be cleansed by just a normal catalytic converter pass, are run back through the engine again to basically cook/destroy them to a more friendly form.
     
    #5 john1701a, Nov 22, 2004
  6. Mike Sarmiento

    Mike Sarmiento Junior Member

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    I have started to notice this pretty regularly. I live on top of a very long hill and as I come down every morning I noticed this high rev. phenomenon you speak of. Naturally I'm coasting/breaking all the way down and as I get to the bottom of the hill the revving starts. It doesn't last long but it is a consistent problem.

    Not knowing much about Catalytic converters, do you think this too is an "emmisions purge." I've got 15k miles on my car.
     
    #6 Mike Sarmiento, Nov 22, 2004
  7. V8Cobrakid

    V8Cobrakid Green Handyman

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    I notice this all the time. when i leave my house i get up to speed very quickly. I used to get up to speed slowly but when the engine is warming up it's seems better to just get up to speed without the wait. It doesn't care to go slow when warming up.

    anyways, when i'm leaving the driveway my engine turns on as i turn left onto the street. after i'm done accelerating.. er.. punching it real quick, it will do the rev/"emissions purge"

    I'm used to it.
     
    #7 V8Cobrakid, Nov 22, 2004
  8. mmccking

    mmccking Junior Member

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    is this documented somewhere in the manual?
     
    #8 mmccking, Nov 22, 2004
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