O2 sensor 4wire

[Seth]

On Mon, 1 Sep 1997, John O Hornfeck wrote:

> I saw that someone mentioned a Ford 4 wire O2 sensor.
> Is there any sensors/brands that would offer me an alternative to the
> Toyota 4 wire sensor I have to replace this week?
> Thank you
> 
> John O
> 
> 
My recollection is that a 4 wire is power and ground for the heater , 
groundfor the sensor, in case the exhaust system is "floating" and the 
signal for the sensor signal.  A well grounded 3 wire should work, or use 
the sensor ground to ground the exhaust.

Just an idea

Seth