I was tuning a 2002 I6 last week and when I adjusted tables B1123, B1124, and B1125 in OS 12587430 it would force the 1-2 shift to occur right before 4000rpms at 30mph. It took me about 3 hours to figure out what was wrong as these tables work perfectly in my 2002 OS 12575262. With these values back to stock everything worked fine, but as soon as I set them to anything other than stock with OS 12587430 this weird shifting issue would occur.

Any ideas?