I extended the wires on my O2 sensor so it would reach my new testpipe by soldering extensions on. I have a 95 GSR, 4 wire O2 sensor, green, white and two black wires. Well, idiot me forgot to mark the two black wires when I cut them (one is the neg for the sensor and the other is the pos for the heater, or vice versa, I can't remember, they point is, they are not both negatives). Now I can't tell which black goes to which. The way the are arranged on the plug is different from how they are arranged on the actual sensor.....they don't line up. Does anyone think it would hurt if I just guessed and twisted the blacks together and started the car up, assuming I would get a CEL if the black wires were crossed? What is the worst that could happen if I did cross them? I am not sure what else I could do

 

I thought both black wires are just grounds.. maybe Honda O2's are different than other 4-wires?

 

Just startiing the car I would imagine you would get a "check engine light" if it was inncorrect. . .I don't think the car will blow up.

 

According to my Acura Service manual, both blacks are for the heater + and -. The green wire is the - for the sensor and the white wire is the + for the sensor. If you unplug the O2 sensor and look into the plug part that is connected to the actual sensor, the white is upper left and the green is upper right, then both blacks are at the bottom. If you look at the actual sensor, where the wiresgo int it, the white and green are opposite of eachother as are the blacks

 

Yeah, I don't think it will hurt.......I just realized both blacks are for the heater too, so I do not know if that will give a code or not. If someone is really bored, they could take out their O2 sensor and look at the wires going into the actual sensor, holding it so the green wire was at 12 o'clock. They could then figure where the black wire, let's say the one at the 3 o'clock position, was connected at the plug. It would be connected either by the white wire or by the green wire at the plug. Just in case somebody is really bored.

LOOKING INTO PLUG LOOKING AT WIRES GOING INTO SENSOR

W G G
B B B B
W

 

Ignore that, I tried to diagram both the plug and the sensor...............it turned out crappy.

 

the black wires are heater wires.you can not get them backwards.

 

What will happen if I do.......will a fuse blow or will it just not work???

 

you could fry the ecu if you dont hook it up right,i know someone who did that

 

Damn.........I'll have to look at someones car to see which wire goes where............anyone got the time to look at theirs?
I'd appreciate it greatly.

 

Here ya go:


white o2 wire = wht/red harness wire for o2 signal
green o2 wire = grn/blu harness wire for o2 ground
black o2 wire = orn/blk harness wire 12v heater
black o2 wire = yel/blk harness wire heater ground

LOOK at the harness side of the connector!!