There is another possibility. On the 95-97 cars there is a Underhood Wiring Harness recall. You might have a short due to faulty wiring which is causing both the lower voltage and the sensor drop off. I just had mine replaced since the Positive Battery Terminal had lost all of its Insultaion and wasn't charging the battery. There is wiring that has been replaced near the O2 Sensor's Connector from looking at the work they performed. Just a thought.
