99,000 miles, first code

I got p0137, O2 sensor. Bank 1 sensor 2. Is that the one downstream of the shielded cat on the drivers side? Truck is running fine and I don't believe I have any exhaust leaks so I am guessing the sensor is failing.

 

Probably, or their is a short somewhere. Super easy to replace.

 

Believe its just 2 nuts to zip it out. A shop would still charge ya a handful, haha

 

I would clean the maf and change the air filter for giggles to see if it goes away. It would take me about 30 minutes on my truck. IDK about the v6. Probably just as easy.

Unless it decides to not come out

 

Nope. You need to diagnose it instead of replacing things that probably don't need replacing.

 

Agreed, probably should have said that first. That kind of code can be many different things, sometimes not related to the code.

 

Speaking from personal experience, when it comes to Toyotas, the codes are simply symptom codes, not the actual cause.

 

So True

 

OK, since no one answered my question I looked it up. Bank 1 sensor 2 is the passenger side downstream sensor. I'll have a look at the wiring and exhaust for sure and do some tests. But since it is the only one coding and the truck is running fine I bet the sensor is failing. I am due for a spark plug change and I'll get to that soon. But there is no noticeable misfiring and no misfire codes.

 

You could try running a bottle or two of Techron Concentrate through after resetting the code. If it comes back I think the part is less than $50 for the Denso sensor. Change it. I did this on my 2003 2.7 liter changing both air and oxygen sensor.

 

Stick with denso, avoid Bosch sensors.

 

Yup. I like Denso stuff. I will also look at ToyotaPartsDeal and see what an OEM one goes for.

 

Denso is the original equipment.

 

Advance Auto lists 2 Denso downstream sensors that are an "exact fit". They look the same except maybe for wire lengths but hard to tell if that is the only difference. The more expensive one has 9.45" wire length and the cheaper one has 11.77" wire length.

 

This. So much this. If it does turn out being the OP's sensor (though rare) avoid by all accounts using Bosch sensors. Bosch oxygen sensors are absolute garbage.

 

Don't Jinks me Brother

 

The cheaper one requires you to splice wires versus the more expensive one. The more expensive one is plug-n-play which would be the one I would get.

 

This might help when you look things over.

https://www.fixdapp.com/blog/p0137-code

 

To rule out the sensor, you could always swap bank 1 sensor 2 with bank 2 sensor 2 and see if the code follows. If the code follows the sensor, there’s your culprit.

 

To update this:

I just ran my OBD2 app in live data logging mode with Bank 1, Sensor 2 (the one that coded) selected alongside Bank 2, Sensor 2 (the other downstream O2 sensor) and TPS position. Engine was fully warmed up after a drive and I revved the engine several times. The bad sensor voltage is flatlined at ~0.76v whilst the other one varies ~ 0.1 - 0.4v in real time reacting to throttle position, which is normal. So it looks like the B1S2 sensor has failed. Interesting that since I cleared the code 100 miles ago it has not thrown another p0137 yet, nor has it even set a pending code for it even though the voltage is out of spec and not reacting. I guess it takes a good bit of time for the ECM to set the codes but I don't know how long. In any case the truck continues to run perfectly, getting 22mpg on my last tank that was mostly for a road trip. I still need to get under and do a visual to look at the socket and wiring but 90% sure now that it is a bad sensor.