I have a customer with a 2014 Corvette GS which has an issue I'm unable to figure out.
Only Mods are: AFE intake, Long Tube Headers and mid pipe (no secondary o2 sensors), LT4 injectors and LT4 high pressure fuel pump
Firstly, the LT4 injectors and pump were just recently installed but the issue was happening before as well. After startup when closed loop kicks in the fuel trims start going negative all the way to -25% which actually makes it run too lean and it starts idling really rough. After about a min and half of run time it starts to clear up as the trims go back to zero. When I disable closed loop the car runs way better and doesn't do it and drives ok, but still a little rougher than I'd like. It also has some codes that pop up which I will post a screed shot of. The tune file and datalog are attached as well.
20240206_100957.jpg