Ok so I bought a cheap $40 replacement universal o2 sensor. Now the new one has not plug so wire cutting and splicing is required. My old o2 sensor has 2white wires, 1black, and 1 grey. My old o2 sensor has 2 blacks, 1 white, and 1 green. Now the instructions have a wire color reference, but none of them match up with our problem.

Im not taking a chance of wiring it up wrong so I was wondering what I do in this situation and what wires should connect. Thanks.

Quick response please this needs to be done today.

 

I wish I could help man but I always went for the plug in ones so I wouldn't have to worry about this. Wiring and I don't get along.

 

The two wires that are the same color should be the heater. Measure with an ohm meter they should be 10 to 40 ohms resistance to each other. They are the only wires that have a path to each other with the sensor cold (never test ohms on a hot O2 sensor).

The other two are going to be sensor out and sensor ground. Usually sensor out is a white wire. It's probably the gray wire on the new one. Did it come with an explanation of the wire functions?

Stock wire colors:
black + black : heater ---- connect to white on new sensor
white : sensor out ---- most likely gray on new sensor
green : sensor ground ---- most likely black on new sensor