Where is the 02 sensor, bank 2 sensor 1 in an 02 Mercury Sable?

Husband is trying to replace the 02 Sensor, Bank 2 sensor 1 in our 02 Mercury Sable & isn't sure which side the Bank 2 Sensor 1 is. The engine is a traverse mounted engine, so is the Bank 2 Sensor 1 (02 Sensor) on the far wall side or the front end vehicle side? We have gotten so many conflicting answers, getting very frustrated :) If anyone knows of a diagram for the 02 Mercury Sable for the o2 sensors (need one with the traverse mounted engine, I guess that's sideways as my hubby explained it to me in "girl terms" that would be AWESOME! Thanks, your help is greatly appreciated!!