backpressure? and exhaust fun

[tberk@mindspring.com (T Berk)]

ternil@idol.union.edu wrote:
> 
> So I finally got plates on my car yesterday morning, which is a good thing.
> Not 12 hours later, I think the cat finally gave up the ghost and the exhaust
> failed right in front of the cat. Now, it revs freer, and is LOUD as all hell. I
> mean, I kinda like it, but the only problem is that my car exhibits some
> backpressure. It did it before, when the exhaust was fully hooked up, it
> was kinda quiet, but now its really making some good popping noises. My
> question is this: how unhealthy is this popping noise which I assume is
> backpressure, cause it only does it when I'm off the gas pedal, like using
> the engine to slow me down. Maybe I'm a sadist, but I like it... the car
> seems to run a lot better without that pesky cat and muffler really doing
> much :) .

It's not back pressure, it's the lack of back pressure.

The popping noise is unburnt gas getting past the valves and later
igniting.

I understand valve damage can occur but I can't tell you exactly how
long it will take to do harm.

TBerk