Locate the wire your using for Ground off the TAC, and separate it from any other grounds. Connect it to its own solid ground, and see if anything improves. Mine was throwing intermittent codes related to the DBW system (also a 2002/2003), and improving the ground and re-seating all the plugs helped. I'd suggest unplugging the battery before doing this so its "starting fresh" on the new ground and has a chance before popping any existing codes.
Where is your TAC located? If it were getting excess heat/flex/vibration i could see problems. The PCB boards inside can break solder joints if they are physically flexed.
*I actually had a very weird issue with the U0107 code possibly being caused by MASS magnetic field interference, which is hard to believe, but I have a theory
