I'm not sure if it will work stuffed up the tailpipe but definitely not if it is post=catalyst. On automotive sysytems the post catalyst sensor is only there to measure the efficency of the converter. Pre- converter sensors will swing up and down as the computer varies the fuel input, post-catalyst sensors remain fairly steady, if the downstream sensor varies like the preconverter it means the catalyst is used up.
So on your honda experiment, seeing steady voltage downstream of the cat. is probably normal. I guess you could try setting your rig up on a bike without a converter and see how it responds.