bad smelling exhaust sometimes..

why does my exhuast stink horribly when I drive my 91 dx civic really hard? The engine is stock with only an intake and vortex device on it. I also just had my fuel filter changed and didn't notice much improvement. Could the problem be that the exhaust gas isn't getting out fast enough or maybe the engine isn't getting enough fuel?

mine is from the cat, because its brand new, yours might be your cat also

Do you ever find black soot on ur rear bumper or is your exaust even comming out the back? If you find soot anywhere, you are running a little too rich like me, I get that same exaust smell when I get on it, but if ur exaust is cut off under the car you will usually always get that smell.

99% sure its ur cat, usally when you overwork your car, like with racing and shit, the cat will start to smell like rotten eggs.

I've only seen a couple of hondas that do this, but sometimes if you use cheap gas that contains more alcohol than the sticker on the pump says (yes, many times there is more than the sticker says) there is a sulfur smell. It has to do with our cars being older, and not made to be able to run on gas with a high percent alcohol , thats why it is supposed to be around 10% max. Newer cars are made to be able to run on gas with a higher percent of alcohol, so they don't have this problem.

yeah, i've had a few friends w/ this problem, in there 5th generation civics....can u just take the exhaust/cat off and clean it or do you have to have it replaced/or just professionally done?