just replaced my rear heated o2 sensor.
after installation i cleared codes and wanted to see chart how it operates.
reading was 0.31V and didnt move at all. it should be switching rich - lean, rich - lean right (0.1 - 0.9V)??
I have a y pipe and test pipe but i dont thing it has anything to do with readings my o2 sensor

 

If you have the FSM, check pages EC 192 - 193.

 

I just borrowed my friend's scanner and the rear o2 doesn't seem to move much at idle. It only moves when you raise the engine speed or change the fuel trim percentage (which I did). My rear o2 is bad however. I had to raise the fuel trim a lot more than 25% before it starts to read rich then go back to lean immediately. Also I have the code 0707, which is why I borrowed the scanner in the first place.

 

That setup will totally screw up the rear O2 readings and throw an error code all the time. You have no cats and the function of the rear O2 is to monitor the cats performance.

 

i have had that setup for over 2 year and no CEL. MIL showed up last week with P0141 (heater)