96 aurora oxygen sensors?

I would appreciate it if any one can tell or show me a diagram of the locations of the oxygen sensors on this vehicle, Im getting miss information from all around saying it has anywhere from 2-4 oxygen sensors and i think it has 3 am i right? two in the front behind the radiator on the exhaust manifold, and 1 somewhere by the catyaltic converter. Im confused annd there isn't a whole lot of manuals out there for these cars.4.0 ltr engine

There are 4 O2 sensors:
bank 1 sensor 1 ... engine exhaust manifold (must lower frame to R&R)
bank 2 sensor 1 ...engine exhaust manifold (must remove splash shield to R&R)
bank 1 sensor 2 ... Pre-converter
bank 1 sensor 3 ... post-converter

The above is according to the '96 Aurora Service Manual.

I did have to replace 1 sensor, fortunately it was the pre-cat sensor. (easy R&R)

what is R&R? thanks

Remove-replace