OBD II Oxygen Sensor Code ??Which O2 Sensor is it??

[wynndi]

The ONLY thing that has ever tripped my '96's check engine light is the following code/diagnosis from my EZ-Link diagnostic:

Freeze Codes
P0145 O2 Sensor Circuit Slow Response ( Bank 1 Sensor 3 )


Does anyone know for certain which of the 3 O2 sensors this is?

I COULD disconnect one at a time and run the diagnostic, but 20 degrees laying on my brick driveway isn't happening anytime soon!

Oh! The code pops up only once every 500~800 miles, usually at speeds above 60 and is the same code # everytime.

Thanks and HAPPY NEW YEAR!