This is an updated version of an old thread...
Basics..
you need a wideband that has an analog output that can produce an OBD2 Narrowband voltage output...
in this example, I will use the Innovate Technologies Widebands LC1/LM1/LM2
read your owners manual for detailed info about which colored wires represent the wiring listed below
Basic Wiring
Get Power from the Battery and Ground From the Battery
use a relay to have it switch power on when you turn the key on
Most Auto Parts stores and electronics parts stores will carry the relay.
the relay has a constant DC voltage input, a switched voltage input, a ground, and a voltage output.
you will connect the battery to the constant voltage side and an ignition on dc source will go to the switched side.
your voltage output will go to your LC1/LM1/LM2 +12v power
the ground will connect at the Relay and continue to the LC1/LM1/LM2 ground.
Analog Outputs
the Positive lead will go to your Narrowband O2 "High Signal" line.
the Negative Lead will go to 2 places. Narrowband 02 "Low Signal" and to the Battery Ground.
the reason for this is that the PCM is looking for an 02 sensor..if it doesnt see a hard ground(the narrow band o2 grounds the low side thru the chassis) then you wont have any readings and the pcm will show a constant 450mv
It is Imperative that you take all Grounds back to the Battery Ground.
This will eliminate any ground loops and any ground offsets you may encounter if you decide to ground things in another manner.
I took an old o2 sensor and lopped off the sensor itself so that I had a set of wires to use with a connector on it so I could just plug and play and not have to cut factory wiring.
I got my ignition on power from the fuseblock in my engine bay
I used gold plated double terminals for my battery to be able to hook my power and ground to it.
you may have to play with the settings of your Wideband Device to get it to respond nicely to your vehicle. I had to widen my AFR range represented by the narrowband signal to get it to "switch" nicely