Help needed for a live reading of rear o2 sensor (bank 1 sensor 2)

I have a 219k '01 xtracab 2.7l. I've been getting a CEL with a p0136 code (oxygen sensor malfunction, bank 1 sensor 2) for the last 2 weeks. I have reset the codes/ecu 3-4 times and the codes keep coming back. The only consistency regarding when the CEL comes on is when I have about 3 gallons of gas left. At first I thought the light was only coming on when doing 67mph+/2200rpm, but it just came on while doing about 30mph.

I went to my buddy's house and he got a live reading of exhaust/emissions flow with his scan tool and we noticed something that didn't look right- the reading for the upstream o2 sensor was hovering around 3.2xx but the reading for the downstream 02 sensor just said "0" and didn't change, which seemed suspicious. I have a URD o2 "simulator" (which is basically a conditioner, working in conjunction with the downstream o2 sensor) with one cat and until now, my truck has been running absolutely amazingly since I installed it 3 months ago.

Ok that's all the info that I can think of. My question is this-- can somebody please get a live reading from their 01-04 Taco and tell me what that number for a functioning downstream o2 sensor is supposed to be? I don't wanna waste my time and money replacing an oxygen sensor that still works (yeah yeah, I know, it's a freaking high mileage sensor and definitely most likely the problem, but money is tight and I wanna know everything I can before going out in the freezing cold to work on my truck)

Thanks guys!

 

That sensor is junk.

The sensor in question won't cause drive-ability problems. It is there to monitor the efficiency of the converter. the light will return every time you reset it due to the sensor being junk. Until you pull the light bulb the light will shine. You change the sensor it should stay off unless you have other codes.

 

Yeah after typing that I realized that there probably wasn't even much point in asking the question, cuz all the evidence points to a fried sensor. Starts with a p0136 then the infamous p0420 bbq'd gato code shows up after a while, which can be/is a result of the 136. I just reset the ECU to see if the same code(s) would show up each time, and they did. Ha, yeah I know, I'm paraniod and ocd, but whatever. So, on to ordering a new o2 sensor for myself...
Thanks

 

Can you swap the sensor with one of the other ones on the truck and see if the sensor readings change? If nothing changes you may have a wiring problem.

 

Na, I can't swap it out with another one. I mean the thing does have 219k miles on it... it is original and will most likely have to get cut off/out since the mounting studs and nuts are basically fused together/to the pipe with rust

 

just ordered a Denso downstream o2 sensor from Rockauto w/ the Tacoworld discount. Good price and the have a good return policy, so I should be ok if I find a different cause to the problem before the part gets here

 

Did that O2 sensor fix the error code?

 

Remove the URD Sim. See if the problem continues. If so, replace the sensor.

If not call URD.

URD carries the full line of Denso O2 sensors as well.

G