in search of the root of poor gas mileage i did a measurement of my O2 sensor voltage on my 84 245 this morning. all measurements were done at idle with the O2 sensor still hooked up to the ecu and the car at normal operating temperature.

when i introduced a vacuum leak, the voltage quickly dropped to ~0.001 volts.
with the vacuum line off the FPR and the vacuum line plugged, it would jump up to ~0.850 volts.
at idle (everything plugged in) it read ~0.790 volts.

to me this seems high, should be closer to 0.550 volts or so right? is this an indication that the ECT sensor is bad or that the AMM needs to be adjusted? it appears the FPR is operating correctly...