Softronic ECU flash will fake the value that the ECU reads in the secondary O2 sensors. I'm not sure if the secondary O2 sensors can be completely removed, however. Go here and call the number:
www.softronic.us Talk to Scott and he will tell if you can eliminate O2 sensors entirely or if you need an additional bung somewhere. Also, there is lots of info on Softronic flash over at caymanclub.net. Search on snap-flash and look for the thread that's 20+ pages long. BTW, I have no affiliation with Softronic. Good Luck.