I just bought a 2011 6.7 Powerstroke and I went to go get on the interstate and it wouldn't accelerate and went into limp mode. It's at the ford dealer and the techs said its a egr problem. Could I go buy a mini max and exhaust so I can delete it or does the egr have to be fully functional before getting it tuned? I wanna delete and this just gave me a reason. Any help is appreciated!!