I recently had my transmission and torque converter replaced and didnt even make it home from the shop and got a check engine light, checked it with trinity and it was bank 1 lean(PO171 if I remember right). Called the shop and they said bring it back so we can look at it. They removed the one of the headers and exhaust to get the trans out. They checked the exhaust and no leaks and the o2 sensors are working correctly. They are saying since they had the battery disconnected for a extended period of time that the pcm reflashed itself back to stock. Say I should reload the trinity tune and that should fix it. Have heads/cam/intake/exhaust. Ive never heard of that happening, is it possible?