[TurboFamilyNY]

Hi Subaru friends, hope all is well. So I've been getting the following Diagnostic Trouble Code (DTC) intermittently for the past few weeks:

P0137 Powertrain – O2 Sensor Circuit Low Voltage (Bank 1 Sensor 2)

Instead of relying on a shop or the dealer to pull the code, I bought the OBDLink LX Bluetooth adapter and Torque Pro app for Android. They work flawlessly so far...great investment and very fun to use.

I have a 2015 Forester XT with close to 50,000 miles, so I’m guessing the sensor is on its way out (if not already shot). I prefer to do the work myself, if possible, but I have a few questions that I can’t seem to find online if someone can help:

1.) Does anyone know the exact location of this sensor on our Foresters?

2.) Does anyone know the exact OEM part number for this sensor?

3.) Anyone have tips, tricks, or suggestions? This is the first time I’m working on a vehicle sensor.

Thank you!

 

[Snow3d]

​

Bank 1 sensor 2 is going to be the downstream unit. Located post catalytic converter. Should be easily visible by looking under the car behind the front passenger wheel. The wiring harness connects near the top of the transmission.

It's a Denso unit. Denso part # 2344988 or Subaru part # 22690AB010
RockAuto has them for around $90. That is about half of what the dealer will charge for the part.

I like to change O2 sensors after the car has been running as soon as the exhaust is cool enough to touch. Whacking the sensor bung a few times with a hammer never hurts either. This usually makes it easier to remove.

You will need a 7/8" (22mm) O2 sensor socket or an open end wrench to remove it without cutting the wire. If the connector is small enough you may be able to unplug it and slide the box end of the wrench over it to give you more purchase vs the open end. If the thing is stubborn, which many are, you may need to lop off the wire and get a regular deep well socket on there.

You might even be able to do the job without lifting the vehicle if your arms are long enough.

 

[TurboFamilyNY]

Super helpful, thank you! Sounds like a very doable weekend project plus I can save myself some money. If anyone has anything else to add, please chime in! :Banane35:

 

[spooky1]

I removed my rear o2 sensor a couple of weeks ago due to same code.A few tips: remove front left wheel for easier access. spray a little penetrating oil on the area where screwed into exhaust. I easily removed mine with an open end wrench. My sensor was covered with soot, blew off with compressed air and the code has remained clear since.

 

[DaFish]

I am trying to attempt the same o2 sensor replace this week, but from what it sounds like Snow3d and spooky are giving conflicting info of which side is the Bank 1 Sensor 2.

"behind front passenger wheel" and "remove front left wheel"

Am I being ignorant or are these two different answers?

Just trying to figure out where the actual location of the Bank 1 Sensor 2 is located.

Thanks!

 

[DaFish]

Update, it is indeed behind the driver's side tire for anyone needing this info.