superchrgds2k

I have a Pro-Comp, Air/Fuel Ratio Gauge that I am installing on my 2001 S2k. I have a paxton supercharger on the car and would like to see what is going on. My question I have is:
Where do I connect the wire that tells the gauge how lean/ rich the car is currently running. I know how to hook the power and ground up.
I have read that you hook it up to O2 sensor (if so, do I have to run a wire all the way under the car to the O2 and tap into it?)(which one if so, I believe I saw more than 1 wire on the harness that clicks into the senser on the catalytic converter when I changed my clutch.)
I also heard you could tap into the ECU, which I would think would be more difficult with finding the correct wire, but a shorter distance to the gauge since the gauge will be on the driver side pillar.
I just want it to look clean and work well, thanks!!

spets

You'll want a Wideband o2 sensor. Hooking it up to the factory narrowband sensor will just give you a lightshow without any real information as to how rich or lean you are.

As for which sensor, you'd want it to be the primary sensor before the cat. I haven't done this myself so I'll let someone else with experience chime in on how to wire it all up.