Exhaust squeal from close to turbo on 07 dodge dually?

over the weekend i bought an 07 dodge 3500 dully with the 5.9 mins and it has a loud squeeling noise alost like a belt going out coming from somewhere around the turbo when driven, it only happens when the turbo spools up, the dealer told me its the exhaust flange behind the turbo but im not sure if i believe it, there is no build up of black soot around the flange, any ideas? anyone had this problem? truck has just over 100,000 miles