I have tryed and tryed to switch over from OS-09381344 to OS-12212156 and every time i do i get a flashing SES light but no codes ive tryed four differant times and get the same thing.And i have a custom tune for my LS2 418cid. This for a 2000 WS6 TransAm M6
stock tune_0001 factory tune.tun
main tune _418cid. #2 nos installed.tun