I apologize ahead of time for having only a fair to partly cloudy knowledge of this Duramax. We did egr delete. Ok at first. Been getting low coolant warning. Heater in cab isn't working (Brrrr!) and there's a bunch of coolant in front of the truck-passenger side. We put a vacuum on it-no leaks. Don't want to damage it more by driving it. More than likely you'll need more info but that's the gist of it. 😭 I want to drive it again!