So i swapped a motor out on an 03 montero sport 3.0L since that the tranny will not shift up until high RPM. i feel like i left something off or got something crossed. motor runs fine otherwise and tranny had no issues before the swap. what am i missing? no check engine light or codes. btw motor was swapped out due to high kms and intermittent overheat issues.

 

Check to make sure you did not miss some connector. Often it helps to physically disconnect each connector and re-connect it again. It may seat the contacts properly. Also check the grounds to the transmission to make sure it didn't get missed.