If you remove the cat, and replace it with a test pipe, the cat effect wont be a problem.
The point of using the post 02 for a lc-1 is to get a real time AFR reading inside the cabin.
Sure, but there is no point to wire it to the ECU, which is what I was saying.
Btw, on a wideband ECU there is a much sexier solution for showing AFR in cabin - ME7Logger on tablet and WinLog dash