Just found out that my brothers was a blown turbo. Dont have any more specifics than that, but the turbo is getting replaced. Seems to me to have been the best possible outcome - bad fuel would have been a nightmare with their tanks, and an EGR system going bad that soon would likely have been an ongoing issue. Dealer did tell him that if the turbo blows again, he'll give them a new truck (advantage of having a small town dealer).