Oil catch can?

I recently bought an oil catch can for my vehicle listed above Flex Fuel. The intake manifold block off plug it came with doesn’t fit properly and I can hear air being sucked in and it is causing two lean engine codes. I couldn’t find any replacements that are compatible with the aluminum intake manifold. What do you think would be the best option to help the plug seal properly? I was thinking of trying to find a thicker O-ring but I'm not sure if it would seal that way.