I lied. I get what you are saying you take it out of the loop. However your problem shows up after a period of time from what you explain. And as I thought, and Rodger has confirmed it can not wet a O2 sensor enough to kill it. So as it stands you have a good O2 sensor after applying heat to it and burning some substance off of it. You have another that did not wake up after the same heat treatment and is dead. What happened to the original/factory O2? It just fascinates me that 1 O2 played dead so to speak, and another is. I do not think I ever had a O2 sensor on anything go out. I am sure fascinate is not the word you would use. I can tell you on my wide band there is a fresh air calibration where I remove the O2 from the bung and hang them in a fresh clean air stream, hold some buttons down on the PC V, and it calibrates them. If it is not gas, then it has to be oil, if contamination is the real problem? Again I am rooting for you.