The page you referenced had as one culprit: external oil spillage. coincidently I had the leaky oil pan gasket syndrome, and the leak got down onto the o2 harness. Hmmmmm. I had wondered if there was a connection. (get it!) I have fixed the leak, and replaced the o2 in the meantime, but still got the o2 failure. It took a little longer to "blow" the o2 (5000mi) that time. Maybe I will spray more more brake cleaner into the harness and blow out with comp. air. Again. I guess oil in the harness plug would reduce the amout of volt. getting to the computer; although the inside of the plug "looked" clean. One possibility.