O2 sensor wiring?

1996 FORD MUSTANG
195,000 MILES • 3.8L • MANUAL
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FRAZIER88
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Ok I bought an aftermarket O2 sensor that has 2 white 1 gray and 1 black wire on it and need to know which one goes to which one. Car has fat red fat white with black line then 2 skinny like a weird green with red line and red with weird green line. Little help please?
May 4, 2026 at 2:16 AM
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STRAILER
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You need a connector view of the sensor, for most 4-wire universal oxygen sensors with:

2 white wires = heater circuit wires
Black wire = sensor signal wire
Gray wire = sensor ground/reference wire

Fat red = likely O2 heater power
Fat white with black stripe = likely O2 heater ground
Skinny green/red = likely O2 signal or signal return
Skinny red/green = likely O2 signal or signal return

Check out the images (below). Let us know if you need anything else.

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May 4, 2026 at 3:16 PM