Code PO756?
Shift Solenoid B Performance or Stuck Off/
2-3 Shift Solenoid Valve Performance
This could happen because the solenoid is bad or it can also happen if the 3-4 clutch is bad . Another possible reason is with a high stall over 3000 normally the PCM becomes confused and does not thing the shift has actually taken place.
https://ls1tech.com/forums/showthread.php?p=8993762







