Codes given are:

P 0125
P 1155
Bank: 2
Sensor: 1

I believe this sensor to be on the front of the engine of the car. Is this the oxygen sensor, or the air-fuel sensor? Also, is this considered the upstream or the downstream sensor?

Thanks!

 

I'm reporting that I did Bob's modification successfully on a 2002 Toyota Highlander. (The black and clear wires were right where they were predicted to be.) There are pictures.

However, I used a "screw terminal block" to make it easier to restore the wiring to normal if the future requires replacing both sensors. (Grainger part# 6HY99)

I suspect the "knocks" the sensors are detecting may be "micro-knocks," similar to how ABS could be viewed as "micro-braking." I'm not one bit worried that my 225k+ engine will be "damaged" because a sophisticated car computer--which cannot determine that a sensor has failed in the first place--will make the wrong determination. I'll say this: the same computer was certainly destroying my transmission before the fix.