P0138 and P2195

Hi All,

Been fighting these two codes for a while. Truck is a 2007 4.7 with 312km. Usually it’s just the P0138 codes, but every so often they will trip together. I replaced the downstream O2 sensor (Denso branded), however the P0138 code came back shortly after.

I did notice that when I was replacing the downstream sensor, the sensor I took out looked like an upstream sensor, from the holes on the sensor end. Referencing this denso document. My replacement had many holes and the one I took out had few, not really sure if there is any significance to this, but from Denso’s literature it looks like the sensor with few holes should be the upstream sensor.

I tried to take a look at the voltages when I was driving today, and it looked like most of the time the downstream sensor was hanging around 0.9volts, although it did fluctuate down to 0.1. However Bank 2 sensor seems to fluctuate much more than the one I’m having trouble with, it spent most of its times near that 0.9 volts.



https://densoautoparts.com/Portals/...wQGG-Z3HNIQPzt8F6nSnQYTZc9Dm7qQwJDjMprHMtrV7w