so i hooked up my airfuel gauge from glowshift. now i know the 05 cavalier has a four wire o2 sensor. does anyone know what wire to hook the gauge up to. there are 2 whites a black and a grey. its not the grey. i tried that and got no reading. the black has to be ground and idk what the other 2 do. so does somebody know so i dont tap in to every wire?

It is the black wire. It actually corresponds to the purple wire on the other side of the connector.

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