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Possible transmission issue

Discussion in 'Gen 2 Prius Technical Discussion' started by Danielle Antol, Sep 3, 2017.

  1. Danielle Antol

    Danielle Antol New Member

    Joined:
    Sep 3, 2017
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    Location:
    Texas
    Vehicle:
    2008 Prius
    Model:
    I
    Hi all,

    I own a 2008 Prius with about 148k miles on it. I've noticed that when I'm driving and I take my foot off the accelerator, it'll jerk a bit and kind of hesitate. I have had it driven by a good mechanic and was told I needed to replace the cat converter, however, I have been told my other mechanics that it does not need immediate replacement. I have been told my car runs really well and there are no other concerns. That mechanic has told me that it's the catalytic converter causing a jolt because oxygen or appropriate amounts of fluid is being sent to the engine. Although, the other day while i was driving and I let my foot off of the accelerator, it jerked twice and then there was a vibration. That was the first time this had ever happened to me.

    I was going to have someone go ahead and replace the cat converter, however, I'm starting to think it could be a transmission issue. I am only getting one code when I have had diagnostics done and that's the cat. If I had a bad transaxle or failing transmission, wouldn't I get a code? Could I be a bad wheel bearing?

    My car accelerates good, I haven't seen a huge drop in my mph, and I still receive power when accelerating. Does this mean I have a failing transmission?

    Thanks in advance for all the help!!
     
    #1 Danielle Antol, Sep 3, 2017
  2. Kevin_Denver

    Kevin_Denver Active Member

    Joined:
    Mar 18, 2016
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    Location:
    Denver, CO
    Vehicle:
    2009 Prius
    Model:
    N/A
    The Prius computer is very good at reporting what is wrong, especially when there is a single code. If the code you have points to bad cat, I would go get a new one. Note that as was recently pointed out to me, you can get a compatible Magnaflow cat for ~$100 off Amazon (don't know the exact model - google around). A muffler shop can pop it in for less than two hours of labor. It wouldn't surprise me if the Prius computer begins making the engine behave strangely in response to a bad cat.

    It's normal for there to be some small jerks when the engine starts/stops below 40mph. The intensity of the jerks increases as the transaxel fluid thins and the motor mounts harden with age. If you haven't already, I would change out the transaxel fluid with some Toyota WS ATF (same as comes from the factory). Toyota never calls for changing this fluid, but the general consensus on these forums based on used oil analysis is that it should be changed about every 60k miles. I noticed smoother starts/stops after changing mine.
     
    #2 Kevin_Denver, Sep 4, 2017
  3. Danielle Antol

    Danielle Antol New Member

    Joined:
    Sep 3, 2017
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    Location:
    Texas
    Vehicle:
    2008 Prius
    Model:
    I
    Okay, thank you! Honestly, I have never been told to change out the transaxle fluid or transmission fluid, I'll call around today to see if there is anyone available to do it!
     
    #3 Danielle Antol, Sep 4, 2017
  4. HBS

    HBS Member

    Joined:
    Mar 30, 2016
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    Location:
    MO
    Vehicle:
    2009 Prius
    Model:
    Two
     
    #4 HBS, Sep 8, 2017
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