Did you set the OTC to English? The OTC defaults to a metric reading at start-up. Before entering the year, hit F1, then 1, then enter. The OTC will respond ENGLISH. As far as the O2 reading, you probably already know this but it has to be 600 F before the sensor responds.
In addition to this, with some vehicles if you leave the car at idle for too long it will throw code 44, (lean). This is because the sensor will cool down and drop below 600 F and the ECM is not getting a reading. (Some folks wrongly assume that the ECM should compensate and go rich once this happens, but it won't).
