Harley Davidson Twin Cam 88 emitting gas vapors?

I own an HD FXSTB with a TC 88. I recently added the Screamin Eagle Heavy Breather to compliment the Performance of my Vance and Hines Short Shot Pipes. I had the breather professionally installed and the Download done by the dealership (Fuel Injected). However, my fellow bikers complain that when behind me they get a vapor smell coming from the pipes. Is this normal when running performance pipes and breather or did the dealership mess up the download. Any advice is appreciated.