I don't drive my '89 200 much anymore and I notice the other day while
hard on the gas a dusty-blackish soot coming out the back... at first I
thought it was just dust from the street but then followed the better
half later that day and saw for myself that it was coming out of the
It will only do it at high RPM under full throttle (1.4 bar) yet if the
engine has been running for a while it doesn't seem to be there. Matter
of fact today after a 100 mile run to San Diego, I took off from a toll
booth, full throttle up to max RPM (1.4 bar) and it was clean with no
visible signs of the soot.... Any idea's on what this could be and where
SO.. I replaced the original rear muffler and catalyst converter about
four months ago, the middle muffler is still original (parts were not
available and I haven't had time to have that one replaced plus it is
still in good condition) and I replaced the O2 sensor late last year.
Also sometimes I get a really dusty smell from the exhaust as well as a
sulfur smell every so often... it was there before/after the catalyst
swap. My thinking is the middle muffler, at 15 years old could that be
producing the dusty black soot at higher RPM's?
Oh and earlier this year when it was cold and the car was warming up, it
would leave a wet black mark on the concrete that came from the exhaust.
it wasn't oil or oily, just black like it was wet soot.
Thanks for any advice as always :)
'89 Audi 200
'03 Audi S6 Avant
'98 Jeep Cherokee Sport