Magnaflow exhaust rattle at low rpm question....

[kchummer]

I searched this but really didn't find an answer....anyways, I have a Magnaflow exhaust and when motor is cold or just started, at a low rpm (2000?) I have an annoying rattle vibration sound until I rev it up and move on....but it only does this when the motors cold, once warmed up it goes away.....anyone familiar with this? maybe a heat shield or mount...not for sure...any help is appreciated