Oxygen Sensor Circuit No Activity Detected (Bank 1 Sensor 2)

Just got this code today. Checked wiring and didn't see anything out of place.O2 sensor was replaced a month ago.Car runs fine.Car is stock.I reset the code to see if it comes back.If it does,are there anyway to check the O2 sensor or see if the harness is getting power? I'm not aware of a fuse that would cause this?Thanks

 

do you have a scan tool, of a laptop datalogger, like datamaster?

if so check the o2 sensor readings they should be somewhere between 391-491 mV

 

I do have a scan tool that gives me codes and freeze frame data,but I'm not sure if it gives me the O2 sensor parameters.

 

be sure to check in closed loop.

 

Switch left and right O2 sensors and see if the code changes. If it does, you know the sensor is bad, if it doesn't the problem is somewhere else. Also, make sure there isn't a heavy carbon accumulation on the sensor. If there is, it can cause bad and inconsistent readings because the flow of exhaust across the sensor will be restricted.

 

I went and checked again and found the hose that connects to the back side of the air intake had come off.Could this had caused the SES?

 

That will be unrelated to your 02 sensor problem. I would do the two suggestions posted above, either put it on a scan tool and get some live data or swap the sensors and see if the code follows to the other bank.

 

Drove around for a couple miles and no light,yet. Going to go out agian and see what happens. Are there anyway to check to see if the harness is getting power? The harness has four wires and I don't know which ones to probe to see? Switching the sensors would be a PITA. It's like 25 Degrees outside.Thanks

 

Two wires in the harness supply power to the heater in the sensor. If that circuit was faulty, you would be getting P0141. The other two wires are for the O2 sensor element, and the PCM supplies 450mV on that circuit and the self-generated voltage across the sensor element adds to or subtracts from that value. P0140 sets when the voltage on that circuit stays between 391-491mV for 1450 times out of 1500 samples. If your light went out, it may indicate an intermittent problem with the wiring or with the sensor itself.

A vacuum leak on the back of the intake manifold (not sure what hose you are talking about - the only ones in the back of the intake would be for the EGR valve or for the FPR) would not set P0140. The vacuum leak would have been addressed by the pre-cat O2 sensors, and the A/F ratio would have been corrected by the PCM. The after-cat sensors are just monitoring the efficiency of the catalytic converters.

 

The light went out because I erased it. I drove around some more and it is still off. The hose I referred to was the black tube that connects to the incoming air duct near the MAF sensor.Looks like it runs to a pump or something near the front of the car. So I should just wait and see if the light comes back on? The O2 sensor is under warrany,so replacing it wouldn't cost me anything.

 

Well,
The light is back and I now have a P0300(random misfire)code. I assume that the previous code is causing this once since the O2 sensor isn't working correctly. The O2 sensor I replaced was behind the exhaust manifold,so this code is telling me that the other one isn't working,right? where is that sensor?

 

found a loose wire on the #2 O2 sensor. Fixed it and the light hasn't come back on. so far no SES and no pending codes in the computer.