I have an 03 X w/7.3 and an Evolution II. Also have an S&B intake and a 4" exhaust. I have an intermittent "funny" sound at times ONLY when pulling my camper. Its sort of like a "popping" sound, very hard to describe. Its def. in the turbo realm of things as it wasnt heard pre-mods when towing. Is this the infamous turbo surge? What other possibilities could it be? Fixes? Any help is greatly appreciated.