Replacing O2 Sensor(s)

[LordHuron95]

Hello all! The vehicle in question is a 1980 vanagon. The first picture is of the sensor I was planning on replacing, located in/on the catalytic converter, though I'm having trouble finding the wire/where the wire should be going to. The second pic shows an O2 sensor after the catalytic converter and is indeed wired correctly.

First question, are there supposed to be two sensors or is this due to a hack job by a previous owner?
Second, where does the wire need to go to or does anyone have a diagram I can follow? Thank you!

[Howesight]

No factory Vanagon, air or water cooled, used dual oxygen sensors.

Most likely, a previous owner purchased a new catalytic converter (which comes with an oxygen sensor bung) and used an old oxygen sensor to plug the bung hole in the cat converter. The oxygen sensor with the wire attached is the one your ECU is connected to.
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'86 Syncro Westy SVX

[LordHuron95]

[DanHoug]

realize, with a single sensor system, using an O2 sensor AFTER the cat is wrong and will give wrong information to the ECU.

in 2 sensor systems, one with a sensor in front of the cat and one after, the front sensor is what regulates the mixture and the post-cat sensor is there to tell the system the catalytic converter is still working.

you really need to put a functioning sensor PRIOR to the cat. but i suspect your catalytic converter MAY be gutted and so the sensor AFTER the cat is fine for regulating mixture.
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-dan
60% of what you find on the internet is wrong, including this post.

'87 Westy & '89 Westy both 2.1 4spd

Past projects can be found at--
www.thefixitworkshop.com

[Howesight]

Hey Dan:

Out in Minnesota, and every other place that is not California, the 1980 Vanagon engine had no catalytic converter. In California, VW had to make a Medusa-style exhaust system to get the exhaust gases through the one CAT. So, on the OP's exhaust system, believe it or not, the gas flow is from rear of the CAT to the front, then through a U-turn fitting, through the California-only heater box rearward, then through the muffler.

In short, the exahust gases do hit the OP's oxygen sensor BEFORE the CAT:

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'86 Syncro Westy SVX

[DanHoug]

all i can say is... "Uff ta"

exhaust, in my reptillian brain, should never flow against the direction of travel because, well, you know, it's wrong. same with electrons. but i did learn something about the CA exhaust, may i never have to see one on an AFC.
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-dan
60% of what you find on the internet is wrong, including this post.

'87 Westy & '89 Westy both 2.1 4spd

Past projects can be found at--
www.thefixitworkshop.com

[Howesight]

"Uff ta" . . . I can't say I have heard that one. My American cousins lived in Fargo. Uncle (RIP) was an aircraft mechanic. There were many "Norwegians" in the area, according to my cousins. I use quotation marks because these "Norwegians" were almost, to a person, born in the USA.

Having now speculated that "uff ta" might be a Norwegian language artifact, maybe you can tell us the actual origin.
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'86 Syncro Westy SVX