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Should the CAT glow????

Discussion in 'Audi S4/A4/A4 Cab (B7 Chassis)' started by pompeyal, Oct 30, 2010.

  1. pompeyal
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    pompeyal New Member

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    Hi all, should the CAT glow when running?
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  2. BASS 666
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    BASS 666 BMW aye right dead on..

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    looked this up for you..


    It's NOT clogged (yet) and it's not "doing it's job." A cat normally gets very hot when in use, but NOT GLOWING hot.

    Something is causing raw unburned fuel to be sent down the exhaust pipe where the cat "burns" this fuel. The cat is designed to burn the tiny amount of unburned fuel that comes from a normal engine. Now, if you pour excessive hydrocarbons (fuel) in the exhaust, the cat will burn that too and since it's burning too much fuel it glows red hot. This won't last very long, this is very damaging to the cat. The catalyst can get hot enough to melt. And that won't take long! And when it melts, then you will have a blob of molten metal blocking the exhaust pipe (now it's clogged!) and the engine will stop operating. At that point, the only fix is replacement of the catalytic converter.

    However, if you find and fix the problem now you can avoid that expense. You have to find why raw fuel is going through the engine. The most common reason would be a bad spark plug or bad spark plug wire. If the spark doesn't work, there is no "combustion" in that cylinder and the raw unburned fuel goes out the exhaust pipe.

    A spark plug can be replaced for 0.97 cents, but if you wait till the cat melts, well those can cost $100's or more to replace.

    Other problems could be a bad carburetor mixture, bad computer causing overly rich mixture, clogged fuel injectors, even bad /burnt valves and/or rings but heck lets not think about that.

    But get an expert to look at it NOW and don't drive it any more till it's fixed, or that cat will melt and then you'll be in deep do do.

    Good luck.
    #2
  3. ukdan
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    ukdan Member

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    Could even be injector failure causing excessive fuel to go through a cylinder.
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  4. phoenixv6quattro
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    phoenixv6quattro staylowmovefast

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    It is actually very obvious as to why it is glowing. There is a dragon living in it. Sell the car before you get eaten. The forcefield of the mighty "CAT" will not contain her forever....YOU HAVE BEEN WARNED.
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  5. BASS 666
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    BASS 666 BMW aye right dead on..

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    what are you on ??
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  6. drmole
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    drmole Active Member

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    lol fairplay theres something in the water up your way lol
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