O2 sensors- 3wire and 4 wire.

[labyas]

I've got 4 wire O2 sensors in my car right now and the female (vehicle side) only has 3 wires because it's an 89. So the missing wire is the heater ground I would assume. I'm running rich and I'm sure that these are the culprits. They only read .1-.3 volts on my B.O.B (which is lean).

#1 Can I just ground the missing wire (Heater ground I think) to the Ground of the O2?

#2 I do have a set of 87 3 wires that look to be in great condition but the hardshell is different. How can I test the sensor so that I can repin them to the 4 wire hardshell?

BTW, these sensors were in the car when I got it- this was not my ghetto fab idea.

Any help would be appreciated- It's nice outside and I want to drive it without smelling like I work at a gas station (because of the smell of the gas not because the people who ...nevermind).

 

[jrichker]

Are you sure you have no vacuum leaks? Are the O2 sensors good?

Heating them with a propane torch and measuring the voltage may work to test them.

 

[labyas]

So check between the signal and ground when heating and look for voltage or power it up on the bench and read between signal and ground with heat?

I physically checked for vac leaks and even capped as much stuff off of the tree and intake and didn't get any response. I even checked with carb cleaner

The sensors generate their own voltage so I shouldn't have to power them up to test... Let me know- I dont want to fry anything and my wife will make me sell the car if I ask for another forward on my allowance for something silly like new O2's.

 

[jrichker]

Check between signal and ground while applying heat.