Can I change the upstream O2 sensor without replacing the converter gasket?

Okay. So, have a good night, I'm going to call it for now. Getting up early and replacing part will update then. Thanks again for all your help! Hope you have a good night.

Okay, so the part change went flawlessly easy once clip was off, lol. I went on a test drive; it seems to be so much better but I didn't get to go up hill or higher speeds that's on Tuesday. Got to Home Depot and car was hot. It's never hot because of aux fan get outside water everywhere. The radiator overflow hose was split, and the union gave out is it supposed to be one piece do you know? AutoZone and napa didn't know. Also do you know what this part is? No one can identify best I got is fresh air intake or bypass? The last pic is the overflow hose after union rotted away.

Thanks so much! Just to prove I stick to my word.