Re: Red Hot Exhaust / Melted Catalytic Converter

["David Teitelbaum <jtrealty@xxxx>" <jtrealty@xxxx>]

A glowing catalytic converter is a sign of an over-rich condition with 
unburned hydrocarbons in the exhaust. When these unburned hydrocarbons 
enter the catalytic converter (which under normal conditions runs 
1200-1500 degrees) they burn which causes the temperature of the 
coverter to go over 2000 degrees. It can get hot enough to fuse the 
matrix of platinum pellets and stainless gratings which can cause the 
converter to become "plugged up" or restrict the flow of exhaust 
gases. This is most noticeable as a lack of power at high RPM's.
Besides an out of adjustment fuel system one of the more common 
causes is a misfiring cylinder caused by a bad ignition wire or spark 
plug. Since the fuel isn't consumed in the cylinder it gets into the 
exhaust where it burns inside the catalytic converter. Short periods 
of this don't always cause permanant damage. Over longer times it will 
distort the exhaust system, damage the catalytic converter, 
contaminate the O2 sensor, melt nearby plastic and fiberglass, and 
possibly set the car on fire. Fuel cools, at least unless it is being 
oxidized! I wouldn't try putting out a fire by throwing cool fuel on 
it!!!!! 
David Teitelbaum
vin 10757


--- In dmcnews@xxxxxxxxxxxxxxx, "content22207 <brobertson@xxxx>" 
<brobertson@xxxx> wrote:
> Am on Xmas vacation, so this is first time I've seen list all 
week...
> 
> It is indeed possible to melt the guts of a honeycomb style 
catalytic
> converter. Not sure why (stuff has consistency of ceramic), but I 
did
> so when my car ran too LEAN (remember guys: fuel cools. Until Martin
> G's PRV man diagnosed my re-tuned, hence over-advanced engine -- 
still
> getting used to life without a carburetor -- was so rich I could
> actually hold exhaust tips in my hands). Telltale sign of stopped up
> converter is glowing exhaust AFTER the the thing. I think it's heat
> from added resistance.
> 
> Do you live in an area with emissions testing? You'd be amazed how
> much restriction a converter puts on exhaust flow. And even when
> properly functioning is unreasonably hot.
> 
> Bill Robertson
> #5939