Just a few days ago a friend of mine was traveling through Minnesota and was pulled over by the DOT, he was driving a 2010 Chevy 3500HD not towing a trailer or anything, only mod that is noticeable on the truck is a chrome exhaust tip. They fined him $5,000 for not having a DPF on the truck. Minnesota doesn't do any emissions testing and he is from Montana. I have heard of $35k fines for removing urea injected trucks, but I have no idea on the legitimacy of that. I do know I'm gonna be looking into finding a stock 5.9 exhaust and keeping it around for a rainy day, I believe they could nail a guy for that too if they want