high voltage - S2 means what?

My check engine light comes on with the code for high voltage on O2 sensor #2
Does the high voltage reading mean that the cat converter is failing?
The light started coming on a couple of months ago for a short time then going off. Now it is on full time.
'96 XJ Sport 4.0 HO

Mike
xjnco


5 speed
31"x10.5" BFG AT KOs
3 1/2" mixed lift
AA SYE
4:10's

I had a similar problem with a high voltage O2 code on my '01 XJ. The light would come on intermittantly and then stayed on permanetly after a month or two. I replaced the two O2 sensors before the converter and that fixed it right away. If the catylist in the converter is bad, it will trigger a specific code. Your's should be fine..

x2
bad 02

blasted 1996 (a transistion year)

in the last week I've replaced both O2 sensors.
In the last month I've replaced:
the computer
sensor in the distributor
Crankcase sensor
TP sensor