Heated O2 Sensor Readings?

[EddieC]

I chased down why our remote start system was not functioning and as someone advised it was the CEL that related to one of the O2 sensors (Bank 1 position 2, downstream drivers side). I swapped in a new oem sensor, cleared the code and cured the remote start issue. Unfortunately after about 30 miles the CE light is back on.

I ran a "live" operating scan report on the O2 sensors and that same one has different mV report than the other 3. The other 3 vary but much of the time are around 750 mV. The questionable one is steady around 450 mV.

Is that a problem and if so what could be causing it?

I rechecked the connector and the new connection plug is securely in there. The only thing replaced was that sensor and it's attached wires/plug.
I don't see nibbling on the wires but it is an inconvienance spot to be peering into.

 

[Dustin Jackson]

@EddieC I have heard there are O2 sensors to not use, this might be the case

 

[CaptainAmerica1]

Or maybe the fuel trims are getting adjusted back to where they need to be and it just takes a bit to dial it in…

 

[Fless]

Is the heater circuit working? Got voltage on the two heater pins and will it light up a taillight bulb as a test load?

 

[EddieC]

Is the heater circuit working? Got voltage on the two heater pins and will it light up a taillight bulb as a test load?

Which would those be?

 

[EddieC]

@EddieC I have heard there are O2 sensors to not use, this might be the case

Not to use? It was GM oem used for replacement.

 

[Fless]

Which would those be?

The two heavier wires that go to the sensor. They should be the same color.

This might be of interest:

 

[Foggy]

Once the engine is warmed your upstream O2 sensors will bounce up and down.
Anywhere from 0 mv up to 999 mv. and they bounce constantly. If the output is NOT
bouncing, it's not working

 

[Fless]

You'll obviously have the code for that side. If you go to the trouble to swap those downstream sensors side to side, see if the code moves to the other side.

 

[EddieC]

Once the engine is warmed your upstream O2 sensors will bounce up and down.
Anywhere from 0 mv up to 999 mv. and they bounce constantly. If the output is NOT
bouncing, it's not working

Yes, both upstreams are bouncing from about 50 up to 750+