Just browsing the Summit catalog and I happened upon part #SUM-G4821. It's a short pipe with an offshoot pipe that can be opened or closed with three wingnuts.

If you welded this in as part of a straight pipe, you could go open exhaust in about 2 minutes and then close it back up to go home.

Any thoughts on what performance would be like with the exhaust dumping to the ground after the O2 sensor?

Greg