Exhaust Problem

[jnestico05]

I just recently put true dual exhaust on my '97 GMC Sierra, 5.7. Two flowmaster super 44 mufflers, stock cats. And so theres no confusion, complete TRUE dual, never joining. Now with my stock exhaust I had an airy sound coming out of it also, once I got the true dual put on, now its only my Passenger side that emits this "airy" type sound. Theres barely any muffler tone out of my passenger side, it seems to be only when cold started will it produce tone. Once you drive awhile and its good and warm, its very "airy" and sounds terrible. I dont understand what this is, my driver side is fine. Theres 94k on the truck, well taken care of if this is of any importantance. Thanks