02 sensor wiring help needed.

[adriancork]

Im changing the gaskets and o2 sensor on the exhaust manifolds of my b4 legacy. Subaru in cork didn’t have any in stock. He gave me the Bosch part number and said try online. As you can see the colors don’t match. Old one was a Bosch aswell but even googling the old part number it didn’t show up. Anyway, what way do I join the new sensor to the old connector? Or did he give me a part number for a different sensor?
New: 2 white and one black
Old: 1 red, black and white wire.

 

[BazGF8]

On the new one black is the signal wire and 2 whites are the heater circuit. You need to google what colours are which on you’re own sensor.
Why didn’t you get one with a factory plug on it?

 

[adriancork]

That’s the part number the main dealer gave me so that’s what I ordered. Iv about 12 tabs opened trying to Google it so then I tried here. Even the instruction sheet has 4 wires on it.

 

[BazGF8]

Did you order from the main dealers? Subaru part would have a plug on it

 

[HawkAl]

Measure the resistance between the 2 white wires of the new sensor and check if any combination of 2 wires in your old sensor yield the same results to determine heater circuit.

This obviously will not work if your old heater circuit is open or short circuit.

As Baz said and the remaining wire will be the positive of the sensor.

 

[adriancork]

Figured it out. From the old 3 wire stock oe Subaru Bosch o2 sensor red- heater, black - heater, white is signal. On the plug connector itself there are 3 pins. 2 silver(heater) 1 gold pin (signal). started and let idle for 10 mins, switched off, let idle again for 5 mins. Took it for a spin and running great.

 

[scoobysub]

Great to hear good man

 

[BazGF8]

Handy fix