Downpipe/Exhaust manifold noise?, Dunno whats wrong... Options

[gnetik]

I had to change the downpipe or header pipe, whatever its called(the pipe that connects to the exhaust manifold and ends before the catalytic converter), because of a huge dent. I got another pipe from TAP and also got new gaskets from the dealership. After I installed these items, there was sort of a putting sound(sorta like a quiet machine gun) that came from around the recently installed pipe. I can't tell whether the sound is from vibration or exhaust/air leakage. I thightened the bolts as much as I could, is there torque specifications for the bolts that connect to the exhaust manifold or something? 6g celicas are sexy cars, but if they sound funky, they lose their sex appeal. Sorta like a hot chick who farts and has bad breath... get what i'm saying? haha! Well please forgive my unknowingness, and any help would be appreciated