o2 sensor simulator?

I have a 91 3000GT VR4 that im swapping engines on. the engine i got is a JDM import. the turbos that came with the JDM engine do not have o2 sensors on them. net even a plug where they are supposed to be, and the turbos that were on the original engine did. is this going to pose a problem if i just leave it like that? and if it does ive heard of these o2 sensor simulators... but i dont see how they would really work. maybe for the post cat o2s, but i cant see them working on the o2s directly after the turbos. i hope im wrong cause replacing the turbos is going to require me to drop my engine AGAIN and i really dont want to do that concidering that the o2 issue is the only thing im waiting on to get this bad boy running again. thanks.