SR20DET test pipe

[Probe Dude]

Hmmm, the rear O2 sensor must work completely differently than standard O2
sensors.  Standard ones (even self heated ones) generate their own voltage
due to the difference between the oxygen content on the inside and the
outside of the sensor (it's a chemical generator).  The ECU measures the
voltage but it does not supply any excitation voltage to the sensor.  Also
since it is a great voltage source and a poor current source, it cannot sink
any current so there would be no voltage change if excited (plus it can be
damaged).

There are 3 wire and 4 wire self heated sensors, the only difference is that
in 3 wires, the ground for the sensor is performed through the bung fitting,
4 wires, the ground is handled by a separate ground wire.

Could you point me to the source of your information?

Just curious
Dave

>From: "Raymond A. Kawski" <sr20de@epix.net>
>To: Probe Dude <probedude@hotmail.com>

>Yes but the ECU just monitors the voltage of the line
>it sends power to the Rear O2 on.  Adding a resistor, which the
>rear o2 is, to the line reduces the voltage.