question about using simulated narrowband output from my wideband

[smugfree]

my primary 02 recently crapped out on my AEB swap car.  ive been running without it and have no issues other than a wandering idle that sometimes causes stalling.  before i buy a new sensor ive considered using my plx widebands narrowband output.  however im not sure how to wire it to the ecu.  as i understand it the sensor has a gray wire and a blue wire that connect to the ecu, but which of these should i connect to the widebands output?  how will the ecu get a reference voltage?  will i encounter cold start problems since its not a heated element?
thanks.