Exhaust noise problem

[Davey16]

Hi,
I have a 99 corolla ce, its sounds like a leak from the muffler system when accelerating, had this checked and the shop says they can't find nothing wrong with the muffler, he says its in good shape (never changed it from new )Could this be from the manifold gasket, thought maybe the head gasket might have gone but no coolant in the oil or any loss of coolant.Any help would be appreciated, thanks.

[ilovecorollale]

I had some kind of problem like that too on my 01 le...i thought it was the muffler leak or shaking or something
....then one day i was going to check and dissembled the header but didin't do it but only to the point where i only took off the five bolts holding the header to the engine....then i was tired and bolt it back on (tightly or so) and the next time i notice....no more rattling sound....so it could have been the gasket.I dont know....