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HCAC Bypass Valve

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by solace2483, Jul 8, 2008.

  1. solace2483

    solace2483 New Member

    Joined:
    Jul 8, 2008
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    Location:
    Chicago, IL
    Vehicle:
    2002 Prius
    I have a 2002 Prius, I bought it used 2 years ago. I have had no issues with it until a few weeks ago.
    My check engine light went on and would not go off. So I took it into the Toyota dealer and they said it "needs front pipe sub assembly w/ new HCAC bypass valve". I did some research on this and found some good info.
    I know next to nothing about cars and this was my first purchase from a dealer.
    So they say it will be $2,000 to fix that ($1,700 part plus labor). He said that the valve is sticking and binding and that it is rusted. He said eventually it will either stick open or closed and the car will stop running.
    I don't know how much to trust a dealer, but I don't know where else to go.
    The car has 118,000 miles on it. He also wants to do the 120K service which will cost $550.

    Any suggestions? Do I just go ahead and get the replaced? How can I get a second opinion of someone I can trust? It's so much money to have to come up with.

    Oh yeah, and last night someone must have side swiped me and my driver's mirror is hanging off the car.
    And I am getting the tires replaced tomorrow cause my front passenger tire was completely worn and went flat while I was out of town over the weekend.

    But the main thing is that valve that they say needs to be replaced. I read on here that it was a design problem. Is there anything I can do??
     
    #1 solace2483, Jul 8, 2008
  2. Patrick Wong

    Patrick Wong DIY Enthusiast

    Joined:
    Mar 8, 2008
    18,200
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    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
    Model:
    Two
    The hydrocarbon absorption chamber (HCAC) is a unique feature found on Classic Prius only (2G does not have this). This is located upstream from the catalytic converter and helps reduce exhaust emissions when the engine is cold. The reason that the front pipe assembly is so expensive is because it includes the HCAC and catalytic converter.

    As a temporary measure, you may be able to use high-temperature grease to lubricate the valve mechanism. However that part is quite hot since exhaust gases pass through it, and the lubrication will burn off fairly quickly.

    The car will not stop running if the part fails, but the check engine light will go on and stay on.

    You can also save some money if you can find an independent mechanic to install the part, and buy the part from one of the Toyota dealers that offer a 25% parts discount over the Internet. For example:
    Champion ToyotaWorld
     
    #2 Patrick Wong, Jul 8, 2008
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