Does the '95 have OBD2?
www.plxdevices.com
PLX has gauges that simply connect to the OBD2 connector. O2 sensor is one of the sensors you can display. Looks like cool stuff,
One way to do it without risking messing with the ECU, is to weld another bung on the exhaust to add an
O2 sensor that connects to only to the gauge.
but WHY??