unknown rattle/grumble/buzzing...hard to explain...help!

[QxMan01]

Hey all, I have a very odd noise that comes from what sounds like the mid-rear right side of the vehicle. It's like a mixture of a rattle and a rumble, sounds faintly metallic...it's actually really hard to explain lol. It's not overtly loud, but is noticeable from inside the vehicle. I hear it sporadically when I'm idling; it's a lot more consistent when the HVAC system is on and if it's cold out. Has anyone else experienced the same issue? It hasn't caused anything to fail or act out of the ordinary, but it's very, very annoying. Could it potentially be the heat shields and the same issue others on the board have tried to describe? Any help is appreciated...thanks!

[Pwnin O'Brien]

I would put money on the downpipe heat shield (the one between the catalytic converter and resonator). My driver side heat shield was rattling like crazy so I just took the damn thing off completely. If it's not the heat shield, it could possibly be the muffler has a broken baffle and it's rattling inside the muffler. But I bet it's the heat shield.