i've got a '97 jetta trek and the check engine light is on... i noticed that the exhaust seems to be leaking where the tailpipe and muffler connect. could this be causing the light to come on?

You need to have the codes read with a scanner. Most large chain parts stores like Autozone & Advanced Auto Parts can do it for free.

after some not-too-extensive checking under the hood, i realized that i had a cracked (read: nearly torn in half) breather hose! replaced it and haven't had a problem since.