Alright so this truck comes in and supposedly it’s been to other places for this same issue. It says to change def with normal with engine off key on. So I did that and changed the little def filter in the pump and the fuel filter for the burner. I drove the truck for 30 minutes and all seemed ok. Well it came back to me for the same thing. So now I’m wondering do I change the quality sensors or from what I’ve read look for a bad nox sensor or possibly the def injector. I will say as the truck is running I get a code for zero fuel pressure and another code for fuel pump failure bcm. I’m guessing these are for the dpf burner? Cause the engine runs great and rail pressure is spot on with desired pressure so pretty sure it’s not that.