So i got the swep duals put on the suburban... they have a good sound to them but it also has a fluff... ideling its not to loud.. sound like a older super duity ford with out a muffler.. you know how you can hear that fluff fluff fluff of air while its ideling...

Anway when you give it gas it get louder.... and when let off it does it too..

we checked all the welds and they are good. The guy at the exhaust shop said it sounds like a "baffel" is bad...

 

i did the hammer mod to my case when i had a gibson on my truck, problem was solved...but maybe i got lucky?

 

so your did the same thing.. whats the hammer mod... I have a BFH in the garage!

 

just pull the muffler off and if you hear a little rattle or something sliding, take the BFH and beat it where the noise is to essentially put pressure on a baffle. Magnaflow guys used to dent the **** out of their muff's to lessen the drone...pretty common anymore really.

That or if its new call up gibson and get it replaced lol...that'd be my first option anyway.