old96A4

I have a 2003 3.0 A6 with one of my O2 sensor heater circuits gone I guess. can some one tell me whihc bank is which on this car?? Is it the same as the old A4's where bank 1 is passenegr side and bank 2 is drivers side.
01 sensor is in front of the cat and 02 sensor is after the cat. I know what's wrong just want to make sure I replace the correct one? is there a picture some place. I think its one after the cat. is it hard to replace on this car. I just did the back 02 in my A4 to get it to pass inspection.