On Sun, 20 Mar 2005 19:27:28 -0500, "pick one" <try again!> wrote:
Not coming to Hurc's defence, BUT a partially plugged exhaust CAN
cause engine temp to go up. The reason the exhaust has lost 1000
degrees is because the water jackets and other engine parts have
absorbed all the heat.
However, once it gets plugged a bit worse, the engine does not get
enough air-fuel mixture to produce enough heat (or power) to do much
A previous responder mentioned something about 1996 and newer vehicles
having temp sensors at both ends of the cat.
This is not correct. The have O2 sensors at inlet and outlet - and if
both sensors read the same the computer knows the cat is not
Also, someone mentioned the switching from rich to lean - and
intimated that was required to allow the cat to work, because one part
of the cat (oxidizing bed) required a rich mixture, and the other
(reducing) required a lean mixture. This is also wrong.
The catalyst DOES require a relatively rich mixture to function - but
the switching back and forth from rich to lean is due to the
non-linear nature of the O2 sensor. It can NOT determine the actual
oxygen content, but knows if it is too rich or too lean. It switches
between rich and lean to get the proper average mixture.
There are a few vehicles that use a linear O2 sensor, and the mixture
on these vehicles does not fluctuate. The Civic VX was one good
On Sun, 20 Mar 2005 23:14:28 GMT, 3 dog email@example.com wrote:
Well It might come across that way, seeing as I'm trying to talk down
to your level.
Perhaps you can explain to me how an oxygen lean mixture (egr cycling)
results in higher combustion temperatures. That could be the only
thing that could explain your "interesting" perspective.
Call me a bit cynical but I'd be interested in any real citations from
actual publications you could find to support your assertion
please tell me where i said that
perhaps you can tell me what happens to hot exhaust gas that is
restricted and stand a chance of beiing sucked up backwards
a little is ok
is a egr pintle the same size as 8 ehaust valves ??
Better yet explain how that hot exhaust is being "sucked up backwards" it is the
exhaust side of the pump remember? Better yet explain how that hot exhaust now
well cooler than normal combustion temperatures will cause any damage being that
normal combustion temperatures are at least in the 2000 + degree range. Better
yet explain how a oxygen deprived gas fuel mixture will ignite with enough
efficiency to make even half the normal combustion temperature?
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