O2 Sensor Voltages

[239]

Anyone here familiar with “normal” voltages for O2 sensors? Two of my sensors appear to be functioning correctly and are on opposite voltages. I’ve read before that it should be that way. However, the third sensor on bank 2/3 stays steady around .790 volts. Any idea if that’s bad? I appreciate any advice. Thanks.

I took this screenshot after driving for an hour:

 

[koda2000]

You may find something helpful in the below link...

Part 1 -Testing the Oxygen Sensors on Your Ford 4.0L

 

[fastpakr]

The third sensor is just for monitoring catalyst efficiency, so I'd anticipate it being relatively steady.

 

[koda2000]

The third sensor is just for monitoring catalyst efficiency, so I'd anticipate it being relatively steady.

True. Only the 2 pre-cat sensor really do anything.

 

[Tech By Trade]

Your rat sensors are fine. That is what they are supposed to do, rat out chopped cats.

 

[239]

A lot of good info. Thanks for the replies, I tagged the post so hopefully it helps someone else out. It’s impressive that the sensors are still operating within spec after nearly 20 years.