Instead of putting in a new bung you can put a spark plug extension on the O2 sensor, that will get it out of the exhaust stream so it won't be throwing any codes.

The extension is hollow, about an inch or so long and threaded male and female, they sell different sizes, I forget which size it is but the guy at the parts store had no problem finding one for me.

2001 Sportage, TJ 106's, Everet spacers and bumpstops, Bilstein shocks on the rear, cone filter, Crager wheels, 235-75-15 Goodyear tires. Custom front winch bumper by Dave Scott. Currently DOA, but it is a work in progress.
2011 Kia Forte EX