first noticed this when i was letting my car warm up talking to a friend @ work when i was about to leave..started hearing a very faint sort of putting sound, seems to be coming out of the center of the car and only when at idle under 1000rpm...i think actually only under 800rpm.
ive been paying attention to it and trying to figure it out, then i just remembered the mechanic showed me a weak bolt on my passenger side exhaust manifold at the flange that joins the passenger headers to the cat. it was wearing thin from its age but he didnt have time to knock it out and put a new 1 in at the time so i left it....that was 1.5yrs ago so there is a good chance it just broke.
next, i noticed that when on the highway and i pin it and go WOT i hear a winding type noise, sounds like a very small turbo spooling.(but without the awesome power gains lol)
do these 2 sounds correspond with a slight exhaust leak?
my mechanic said the exhaust wouldnt drop because its dual so if 1 broke it would stil stay hung at its normal height but i would hear it... this is very faint and my friend didnt even notice it till i pointed it out.

maybe its time i finally throw that dual exhaust on that ive had for a little over a year now...what do u think Gaetano? lol