In the plumber's trade there is a wrench called a basin wrench. It is sort of like a cross between a crow's foot and a pipe wrench. It might of helped and it might not of.
Your experience reminds me of the FAX that went around a few years ago. It was titled "never give up". It was a drawing of a bird with a frog stuck in it's mouth. The frog still had it's hands free and they were firmly around the bird's neck, strangling it. The bird had a worried look on his face. The frog still had a chance.
I wonder if the oxygen sensor got worried befor it finally gave up.
