I've heard of moving the sensor before but don't think there is that much to be gained by doing it. It relocates the sensor from the intake to the direct flow of air in the backing plate to richen up the mixture.
I feel the proper way of richening up the mixture is with a tuner of some sort myself as opposed to this method.
By moving the sensor to the backing plate it would be exposed to extreme cold temps in a colder climate and would give false info back to the ECM which would give poor fuel settings in return.
