Excellant Site Big Jim. If you punch in the code P0161 it comes back as H02S22 (Heated Oxygen Sensor bank #2/sensor #2). These (#2 sensors) are called "catalyst monitor" sensors and are NOT used for fuel control. They just mainly tell you if your convertors are working correctly.
They can usually be identified by their blue connecters compared to the green/sometimes white front (#1) 02 connecters.
BTW on all Fords H02S 11 (bank 1/ sensor 1) is always on the side where #1 cylinder is.
