I got a set of these:



Which more resembles the former than the latter, though I wish O'Reilly had one of those. I know better than to use an open-end on something like this

EDIT: I just looked it up, and O'Reilly (my closest parts store) has things like that available as a "Ship To Store" option, but they are either 7/8" or they don't state the size. Nope, not gonna gamble like that...

 

OK, 12" breaker bar fixed that situation pretty good. One grunt and it kicked over. The old Oxy sensor had a nice coating of white soot (or whatever it was) and what looked like some flaky black gunk around the base of it which may have contributed to its demise. The new sensor came with anti-seize pre-applied, which was a nice touch. Got that torqued on, unplugged the battery to clear the codes, re-connected and fired her up. This car hasn't run so smooth since I got it. A drive around the block confirmed my success. I am now a happy man. I'm not going to think about car repair for another week or so (famous last words, right?).

Thanks all, it's been another great Volvo adventure. See you in the next thread, whatever it may be.