O2 sensor eliminator — why?

[Motogeezer1949_imp]

I had my sensor disconnected when I first put on the Yosh, the check engine light would come on but the motor didn't run any differently. I imagine the computer went into default mode as far as O2 input goes. To make the light go off, I hooked the sensor back up and zip tied it in the breeze til the eliminator arrived. Never had any running issues either way.