Ok so i have a 2006 Dodge 2500 quad cab long bed with a Bullydog PMT (Currently Uninstalled) 50+Hp injectors K&N Cold Air and a 5" Exaughst. The Bd completely trashed my torque converter, so naturally i replaced it. all was good until about a week ago i was going to get onto the highway when she wouldnt shift out of 2nd. it finally did but slips like CRAZY i figured out there was too much fluid so today i pumped out the excess and a new code popped up. it was a P0920 - Gear Shift Forward Actuator Circuit/Open. Im not real sure what this code means? Anybody got any ideas?

 

Bad sensor or wiring.

 

So you put the new TQ in? Check your connectors! Did you put a valvebody in? I hope so!!