My 3.2 smells like it's running rich-O2 or lack of cat?

[efhughes3]

I recently put on a euro pre-muffler, and changed my O2 sensor at the same time. Since then, I get a "rich" smell from the exhaust whenever it's running basically. My question is: Does the Catalytic converter do that much to "clean" the exhaust, or could I maybe have a bad O2 senser?

The car runs good, and I don't see any change in the way it runs, it just seems to have that smell that I really notice when either leaving or returning to my garage.

[JDaniel]

If it makes you feel any better my car "smells" a bit more now that I went with a EPM. The cat really does a lot for emissions

Did you replace O2 sensor with a Porsche part, or did you buy the bosch and splice the wires?

[Face]

I recently put a Vertex Cat-Bypass on and I really notice the smell when starting, stopped at a light with the windows down, etc. I think it's normal!

[efhughes3]

I went with the universal senser, and spliced the wires. I figure it's working 'cuz I get the same variance in RPM's right after starting when cold, and the settle down pretty quickly to a steady idle. At least it's the same way it was with the cat and the other O2 senser. I guess I kind of feel guilty now about taking the cat off, I guess they do work. I only hope I'll be OK at emissions time.

[targa911man]

Ed--

Don't know what the legal emissions limits are in Tx, but I had to put a new cat on my 85 to pass in Va. And the cat does work. My emissions went from around double the limit without to zero with the new cat.

[Superman]

If you cat is working, the two things: An over rich lixture will kill it and a rich mixture will not smell so much like fuel, as sulphur. That is what makes cars smell like rotten eggs by the way, in case anyone has wondered. That's the smell of a CAT getting an over-rich mixture. It's the smell of a dying CAT.

[efhughes3]

I don't have a cat, I've replaced it with the Euro pre-muffler, this is what has caused the rich smell. It's not rotten egss, but just potent exhaust.