three wired Oxygen sensor

[pwm74]

I just bought a bosch universal 3 wire oxy sensor. I have to cut the wire coming from the 3.6 liter harness(did . I heard all three wires do not have to be used, is this true. there are one black and two white. does anyone know why there are three.

[cds72911]

There are three wires because it is a heated sensor.

[thabaer]

ground, +12V, and signal.

I have one on the way for my 200tq20v, which uses all three. They often include heaters to speed up reading accuracy when cold, thus 3 or even 4 wires.

[Jim Smolka]

On most 3 wire Bosch type O2 sensor, the two white wires are for the heating element. The polarity does not matter. The black wire is for the signal.

On 4 wire sensors the extra wire is for the ground path for the signal wire. This way the ground does not have to go through the exhaust system thereby reducing noise in the control circuitry. This is a good thing that Ford started requiring on their cars in the late 80's and early 90's especially since the O2 signal is typically less than 1 volt.

[pwm74]

So will any type of connector will do, I dont have the original

[Jim Smolka]

The ideal thing would be to use the old connector from the old O2 sensor and spice that connector onto the new O2 sensor. If you don't have the connector, you might try to find someone who has an old sensor (P-car shop or a Pelican parts wanted BBS)

[thabaer]

Mine arrived today, it has anti-sieze on the threads and a plug attached. The plug looks a lot like a mic XLR with 3 round pins at 9,12 and 3 o'clock in a round housing.

Any idea who would have a mating socket to fit ? I've been looking through the Audi/VW ETKA and haven't seen anything that might work.

Now don't tell me to just lop it off and crimp it to the old wires, I get my kicks by socketing everything!


I just noticed, even the cardboard box has a Bosch part number.

[Roland Kunz]

Hello

The rubber sockets are showed in the spare parts catalouge and can be ordered as repair set.

Grüsse

[pwm74]

What spare parts catalog

[Ned nyna 11]

Guys,
I replaced the o2 sensor in my 87 last Summer.
Um, ah, went with the generic Bosch model, figured, no big deal, I will remove the generic connector and solder the old connector in it's place and live happily ever after.
Didn't work that way as the wires are stainless and solder will not stick to stainless. I spent hours searching for spade connectors and crimped them to the old connector and the new sensor wires.
Should have got the Porsche sensor. Right plug, plug it in, job done.
Hi Roland, offer still holds.
Ned Monaghan