Pre + Post O2s

[Bruce Plecan]

As I understand things, the cat converters are a reducing chemical reaction,
so
they consum calories to react.  (True or False?).

The rear O2 sensor would run cooler then the front.

So, the rear O2 in order to measure the effectiveness of the cat would need
to
operate at least at the same temp as the front.  So it would need a "better"
heater.

Since it might not track the front too well, then it's "range" would need to
be greater.

Only have any documents to compare the above to, or does it make sense
to someone other than me?.
Bashful