Fix PO420 & PO430 Catalyst issue for 10 bucks. O2 adapter fits with no modification.

Here is an oxygen sensor adapter/extender that is specifically made for what you are trying to do here. There's no need to drill anything no special tools required. It's the right size and works right. It comes with the gaskets, it fits and works right out of the box and it's cheaper. No need to mess around with drills and it's easier to use than with those spark plug non fouler adapters which you have to drill. Cost about 10 bucks on Amazon here's a link. You can find cheaper off Amazon https://tinyurl.com/2p836nep