Yes you can turn the O2 sensor off with Tunedit now. However you will have popping on decel if you downloaded any of Wayne's maps. The recipe to reducing the popping is here
http://www.r3owners.net/showthread.php?t=1804 This has worked well for me. You could go even higher in the RPM range if you liked. Since the O2 sensor is disabled there will be no return of the popping.