O2 Sensor connects to ?????
 

What does the O2 sensor connect to in a 965? Mine connects to nothing. There was some GM wiring harness for some aftermarket component that was not installed. Meaning I had a lot of wires going nowhere. What should it connect to?

I'm trying to remember where the 02 plug originates.

<runs out to parking lot>

Does your 02 still have the OEM 3-prong round plug? Mine comes through the left firewall under the fuel accumulator.

They probably set the O2 with it unhooked and left it . I don,t use mine either.

Yes, it does have a 3 prong round plug. Is it not needed for normal operation?

No.

OK, after a little more digging around with the intercooler off we found the other end of the connector. Still don't know what all it connects to but it is connected now.

Do you have the lambda control unit under the driver seat? Next to the K-Jetronic box... that's what the O2 sensor connects to ultimately.

If the origonal narrow band oxygen sensor was unplugged the car has probably had the idle AFR or CO set with it disconnected.

Also the O2 sensor has a heating element inside that helps keep it clean and when left unplugged in a car that is driven the sensor may get filled with exhaust carbon and now it doesn't work anymore making it good for nothing other than plugging the hole it screws into.

Sometimes removing them and heating the tip with a propane torch will clean the platinum part inside and bring them back to life.

If you set 02 and leave it un hooked and are worried about getting carbon on the tip, remove it and screw in a spare spark plug.