I have the A/F gauge for my car but I need to know which wire on the O2 sensor is the signal wire. To my knowledge the white wires are the heat wires then I have a black and a grey wire. So I was thinking the grey wire is the signal wire just cause the black usually is some kind of ground.

I looked on the VFAQ and the turbo dsm's have different wire colors (blue, white, black, black) for their 02 sensors. I'd try 2gnt.com for more information.

I looked there and never found the info. I guess if I get the chance I will call Flash at the dealership and ask him.

Ok just so peeps know whats up. On a 420A motor when adding a A/F gauge use the white w/black line wire before the O2 sensor plug in and all will be good.