I have two catalytic converters. Both thunderbolt high flows with the o2 bung. One is 2.25" other is 2.5" $40 each

Also two flex pipes the one with the pipe extensions is 2.5" the other 2.25. $15 each

None of these have ever been installed. Just ordered them and decided to go on a different direction and didn't get them returned in time. Prices are TYD.

Thanks for the deal on the 2.5 cat! I will be adding it to my build

Is there a way to plug the bung? I need one bad one I only have 1 o2 sensor

Yes you can...

2.5" cat is gone.

I don't see why you couldn't just stick a pipe plug in there to seal it off.