I have an 03 6.0 with an Edge programmer on setting 4. When going a steady 75mph down the freeway, the EGT's will get up to around 1100 and then the Turbo will start popping off, loosing boost and blowing black smoke. Also when the EGT's start getting high, i get constant light smoke then turbo will start popping off. I don't experience this with around town driving, only when at a constast faster speed or when pulling a load. Anybody have any ideas on what could cause this?