I do know Victory works a bit differently, O2 is not always sending a signal to trim fuel.
Without looking at the parts list, I'm pretty sure there's no map or knock sensor here.
If the O2 on this bike is a 4 wire system, unplug the black wire, which is the signal wire and keep the others plugged in. This should keep the MIL off. The ECU just needs to "see" the O2.
Edit; I'm sorry, you don't have a bung.