Hey all, I'm sure it's been asked several times on here, but I can't find definite answers for my question. Anyways I'm already running the sft tune stage 1. But now I'm have DEF issues and getting the count down till engine won't start msg. Going to load the stage 2 tune and replace the exhaust. My question is, do I have to remove the egr cooler and all of that as well? Or can it stay in there for now? Have block off plates on egr already. So am I good to go with just the exhaust? Or do I have to remove other stuff too? Thanks in advance.