My bet is the PO of that car, had a filter or engine replacement in the past, and when he goes to the store to get filter it comes with two o-rings, so he put them both in... that filter is NOT supposed to have two o-rings. only the smaller one. however the CAR should have the 02 housing that DOES use two o-rings.
I'd get the correct housing, with the correct two ring bolt, and swap it in.

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!