I got myself E-manage Ultimate to play with and then an OBD scanner to see what is going on, but as I try to graph log the readings from the 02S1 sensor, the software that comes with the OBDScan Apex gives me an error about the string typing double or something and everything else works just fine. The scanner doesn't show any error codes and all seems to check out, but is it still possible that my O2 sensor is bust? I haven't noticed any difference in driving, but I remember hearing some loud bangs from my exhaust couple of times when testing my nitrous last autumn.

So... if no errors are up, no CEL, no nothing, is it worth taking the O2 sensor out to check it and if so, how do I know if it is broken?