O2 sensor Bank 1, Sensor 2 not showing output voltage

[nfazer]

Using ProScan and an ELM327, I read my Ranger's O2 sensors, and Bank 1, Sensor 2 comes up with no voltage. I assumed this was the sensor behind the catalytic converter, so I replaced it, only to get the same result. Testing the same sensor (Bank 1, Sensor 2) on a different vehicle, the scanner picks up voltage, so I can rule out the scanner or software. Any ideas? Screenshot below:

 

[edog]

How many total sensors are there on the vehicle? Usually the second sensor in a bank is the sensor downstream (after the converter). The voltage reading for that sensor should be low, but not zero.

 

[nfazer]

There are 3; two on the passenger side (Bank 1), and one on the drivers side (Bank 2). Sensor 1 on Bank 2 is before the cat, and sensor 2 (the one in question), is after the cat. I let the scanner sit for about 5 minutes with the truck running, and there was no voltage output. I thought maybe there would be no voltage until the truck warmed up, but that really doesn't make any sense.

 

[edog]

Are the sensor wires in good condition? Have the other sensors been replaced? And are they functioning correctly? Just some things to check.

 

[nfazer]

Wires should be fine, as I swapped out a brand new sensor for the problem one, with the same result. The other 2 sensors are outputting correct voltages. I also have a cylinder misfiring, and have been told that can interfere with the O2 readings. Ranger's going to the shop next week to get whatever is wrong fixed, so hopefully I'll be able to post the mechanics findings.

 

[edog]

I meant the wires from where you plugged the replacement sensor in that go to the PCM. Those wired could be damaged. The misfiring cylinder should show up in the upstream O2 sensor. Please let us know what the outcome is.

 

[nfazer]

Took it to a mechanic today and he said that the EGR valve is rusted on the bottom and the lines are getting corroded. He's going to replace them next week, so we'll see what happens.

 

[nfazer]

Just wanted to update that it was my EGR valve - mechanic replaced the valve and tubes; came to around $350 after parts and labor. No more check engine light. Must be a combo of the scanner/software that was not reading the O2 sensor.

 

[ozmedia]

The sensor not reading is very common with Scan software, most have more PID's than you can ever imagine using.

The most common issue i've found with ELMScan based software misreads for O2 is the PID selection, make sure you are checking HSO2 (11 or 21)SV the sensor voltage for HEATED sensors. As for teh quick O2 test, emissions test, that usually doesn't work with heated sensors, but theu include it with today's software anyway. Most scan software includes basic, SAEO2 tests for older vehicles that didn't use heated sensors.