Just got done doing the swap and had to get the key reprogrammed and the car runs fine but has a MIL. P1520 is showing up. How is everyone else getting around that code. ECM, harness and engine was replaced. That code just keeps popping up after the VIN was changed to correspond to the car's vin. Or do I need to change back to the original vin in the ECM? Any help would be appreciated.