i have a 97 sunfire and bought a megan cat back exhaust and the stupid shop put it on wrong because they had to weld the first part of the exhaust to the cat but now in the morning it has a smooth deep tone to it and then after that it starts to have a put put sound and they said it had a small leak so they patched it up and it still does it. so my question is does anybody know what could be wrong with it? will replacing the cat and the headers and downpipe take care of the sound? thank you

Cover the exhuast tip and listen for the "put-put". Wait till the exhaust is cold first or it might hurt. It sounds to me like you still have a leak.

thanx and another thing i know where the leak was. it was where they had to weld the cat to the exhuast and they patched it up twice and it still did it. there was a hissing kind of sound coming from the cat but thanx ill try that after i let my car sit for a hour