indirocz28

Allright- ive got a 94 z28 m6- and i installed a Faze a/f ratio gauge today- and i am not getting any reading's..- what wire on the driver side o2 sensor do i need to tap into for a reading??

Thanks

396D1SS

It has been along time since I hooked this guage up but I believe it was the purple wire.

indirocz28

this is the purple wire on the actual engine harness before the connector for the o2 sensor correct?

Injuneer

You hook up to the harness wiring, anywhere between the PCM and the O2 sensor plug. Do not cut into the O2 sensor wires.

Drivers side is purple/white wire on PCM pin C20. Passenger side is purple wire on pin C8.

Some people run both sides to a single-pole/double-throw switch, so you can select either sensor to be displayed on the gauge.

When you get all done, its not going to show you much, except maybe if you have a complete sensor failure. The O2 millivolts switch too rapidly in closed loop, swinging from very lean to very rich. At WOT they will be more stable, but the stock narrow-band sensors aren't accurate at the A/F ratios used for WOT.