I have swapped a lbz into a 04 sierra ext cab 4x2 that was an ex 6.0 gasser and got it going without too many issues. After being parked for a couple days, upon startup It shook, white smoked and misfired to the point I'm afraid to drive it. I have an OBD2 bluetooth adapter with TORQUE app and even though the CEL light is on it wont display ant codes. Possible causes/ solutions?