Bad 2-3 shift solenoid!! WTF!! HELP!
Your problem is a tuning issue not a trans issue. You PCM compares the MPH the car is running against the engine RPM , Well due to the stall converter the engine RPM is higher than the PCM expects to see on the 2-3 shift so the PCM thinks the 2-3 shift did not happen , So it sets a CODE PO757-SHIFT SOLENOID B STUCK. Then in turn sets max line and 3rd gear only.
Have the test for that code removed from tuning and you will be all good.
Someone post or calls me asking about this ussually a few times a week after installing a high stall converter.







