YOU HAVE THE CODE ! If you go to the doc with a broken toe does he splint your elbow???
this is NOT your torque converter! First off, it would not act up in second gear as the TC should not be locking up to the engine below 35 MPH! WHy do people look to transmission/torque converter before they look at the engine which causes 95% of the issues. especially when the PCM TELLS them where the issue is located??? YOUR O2 sensor has issues that need to be taken care of before you can diagnose any other issues!