I also had a exhaust leak. I determined it came from the passenger side and while removing the down pipe nuts near the catalytic converter I found that one was loose, the other broke off, and the third stud and nut was not installed at the factory! I replaced everything, the manifold gaskets and the down pipe gasket.
this happened to me last week after a little offroading. one of the manifold to catconverter connection bolts completely gone. other two loose and small gap in the pipe caused it to sound like a monster truck. just got a 1/2" socket and tightened the other two back down now its whisper quiet like a new engine..piece of cake. took 2minutes once i found the problem