I just did some more reading on O2 sensors, to summarize:
Heated O2 sensors allow the sensor to be used for readings more quickly and allow the O2 sensor to be placed farther downstream in cooler locations in the exhaust.
Testing unheated O2 sensors requires the engine to be run at 2500rpm or so to provide a load to create enough heat so they work.
So, based on this, I would think that you are OK using an O2 sensor with a broken heater unless you;
like to warm up your car in the winter by letting it idle for 10 min
,
or, have a huge engine running at very low load most of the time
.
I'll assume neither of these conditions is true for you or your honda, the only other condtion would be idling in stop and go traffic for a long time. This may allow the exhaust system to cool enough so that an unheated O2 sensor would cool to much but I doubt it, maybe at -20.
That all said, if someone gave me a good O2 sensor I would like to try it out and see if there is any difference in my mileage, as I didn't find anyone else reporting about running with a failed O2 heater. I do have to think that since my car is running in closed loop mode that the sensor is reading within the normal range once the sensor is warm and that since I don't idle the sensor gets warmed up quickly enough not to worry about it.
Ian