I've got a 94 del sol si with almost 65k miles on it. Yesterday i was playing chaufer for my younger sister and we were playing music pretty loud, so i don't know when it happened. I first noticed it leaving a gas station. My car is really loud, it sounds like it has an aftermarket exhaust, except the sound isn't so nice... I'm guessing it has something to do with the headers or the connection to the muffler, but not really sure. A while back, when installing a short-shifter, we had the exhaust off before the cat and fired it up to hear what it sounded like, damn loud. Right now, it's not that loud (and i havn't died from any fumes) so i think it's going through the cat. Any ideas???

 

Take it to a muffler shop and let them look at it.