Coolant loss after cat lock fitted

Discussion in 'Gen 3 Prius Main Forum' started by mathewjg, Nov 22, 2021.

  1. ChapmanF

    ChapmanF Senior Member

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    There's a little naming issue going on here that might be adding some confusion.

    The car has more than one catalytic converter. It also has an exhaust heat recirculation system. Which is not a catalytic converter.

    The coolant is nowhere involved with the catalytic converters. It goes into the EHRS, which you can see in this picture, after the second catalytic converter. It's got the coolant hoses attached to it.

    [​IMG]

    It might be that some mechanic is operating on a rule of thumb like "any bulge-y thing in an exhaust pipe, I'm going to call a catalytic converter." But there are bulges that aren't catalytic converters. :) The one with the hoses connected is the EHRS. (The one after that is a sub-muffler.)

    I would kind of expect a Toyota technician to know better.
     
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  2. Tombukt2

    Tombukt2 Active Member

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    So then in the scheme of things that very first bulge up near the red wires is the first converter The second one is right behind it then comes the EHRS and then the pre-muffler or silencer so when a gen 3 this gets really messy the person is going to be trying to cut the second cat out and going to make a mess of probably those two coolant lines and whatever else is in the way yuck. And I guess it looks that shield is going to bolt to the floor of the under floor of the car right there about where that EHRS is and a little forward of that maybe I wouldn't see where one of the clamps did the EHRS would be in the way but that's weird Not sure that the cat plate shop would necessarily be at fault the hose could have just started leaking because it's old

    SM-A715F ?
     
  3. mathewjg

    mathewjg Member

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    Many thanks for the amazing info. It makes sense to me that the fault must be with the hose pipe to the heat storage function but the garage that fitted the cat have confirmed that the fault is with the cat and are replacing it. Thats great news as that means its covered by the warranty so no cost. Perhaps they change the whole lot as indicated in the diagram?
     
    #23 mathewjg, Dec 1, 2021
    Last edited: Dec 1, 2021
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  4. Tombukt2

    Tombukt2 Active Member

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    They're replacing your cat or cat shield the coolants leaking out of the cat?

    SM-A715F ?
     
  5. mathewjg

    mathewjg Member

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    My understanding (which is not based on any real knowledge of Prius) is that the heat storage functionality is separate from the Cat but that it forms part of the Cat assembly and is part of the replacement kit. Someone please correct me if that's wrong, The heat storage system stores hot coolant when the car is parked and it is then transferred back to the cooling system when the car is started. I understand that the CAT works best when warm so perhaps its also used to warm up the CAT? By the way, the original non Toyota cat lock was removed when the new cat loc was fitted and then my son had a new Toyota cat lock fitted. The car now runs much quieter as the non Toyota cat was vibrating and causing some noise.
     
    #25 mathewjg, Dec 27, 2021
    Last edited: Dec 27, 2021
  6. ChapmanF

    ChapmanF Senior Member

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    This part is right, if you are getting the parts from Toyota. You have to buy the "pipe assembly, exhaust, front" (17410 here), with both catalytic converters, the EHRS, the sub-muffler, and the rest of the front pipe.

    [​IMG]

    This part is a mix-up of two different Prius generations. In the Gen 2 Prius (2004 to 2009) there is a thermos that stores hot coolant when the car is parked, and there is no exhaust heat recovery system. The thermos is what helps warm up the engine faster.

    In a Gen 3, there is no thermos, and nothing stores hot coolant when the car is parked. The exhaust heat recovery system is provided instead, and it collects exhaust heat to help warm up the engine faster.
     
  7. Tombukt2

    Tombukt2 Active Member

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    Man I'd hope to have one my LKQ buddies snag that whole assy. Off for me . Buying that would be costly. I haven't looked but by the fittings on that bulbous piece of above what looks to be the real converter I guess coolant flows do that and sits in that a good bit of the time or all the time so I would think that thing would be prone to rusting out

    SM-A715F ?
     
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