My Auterra palm dyno is showing that my O2 sensor (b1-s2) does not appear to be working. I intermittantly get a code PO138. PO139, and a PO435? I think the last is Cat not working up to full efficiency.

My Question, which sensor is this? I could not find that designation (b1-s2) in the FSM. I believe it is bad becasue It only reads from .28-.29 volts. The voltage does not change more than that from a dead standstill to a WOT launch and run to 50mph. I think it is the one right before my cat. I do have a warpspeedy -Y. So I am thinking it is that one.

Any help?

Thanks!

 

its the sensor after your cat

 

the mouse with the "white" tail