I need to replace the O2 sensor in my car now!!! I would like to go with a 3 wire setup for the upcoming header install. I am not ready to wire it up though. I don't wanna buy two sensors though. I would like to buy a three wire O2 sensor but only hook up the sensor wire. I need to know if this will work like the factory setup and read correctly or will it just **** me off and not run right? I can't wire the other two wires yet cause I have not determined where I wanna install the sensor.
Also, where is a good spot to hook up a 12V source? I assume the ground will bolt to the back of the head like the adapter harnesses you can buy state to do??

Thanks for the help in advance

 

In theory, yes, but of course there can be small differences just like there is between different brands of 1-wire sensors.
But what's the problem with wiring up an intermediate supply for it? If you are able to do wiring properly then you should be able to do it in a reversable manner and redo it later if neccessary. I'd just hook it up to one of the pink/black wires in the bay. Ground to head should be ok.
Please note that I don't have actual first-hand experience in using a 3- as a 1-.

 

Yes, you can. A 3-wire is just a 1-wire with a heater built into it. I have used 3-wire sensors from a 92 Vette in F-bodies running headers a couple times. The white wire goes to your current knock sensor wire in the wiring harness, just like stock. The two black wires are for 12V+ and a ground. It doesn't matter which is hooked up to which. It's just an electric resistance heater and polarity doesn't matter. And yes, it'll work without the heater wires hooked up at all- but you'll be basically turning your (more expensive) 3-wire O2 back into a 1-wire.

 

 

Sorry- O2 sensor wire, not knock sensor wire. I was a little tired when I typed that.