installing a high flow cat

So I bought a random technology high flow cat from a local import custom shop that was used came off a crx that had a really bad wreck just recently. They tested it and he said it was fine. Got it for 80 bucks off the guy. He put a new metal looking gasket on it and I was wondering how I would install this. Just bolt it up with the metal gasket or do I put something on it? I don’t think you put anything on it but I haven’t ever done exhaust gaskets before. Also it has a bung on it and since my cel keeps coming on for the o2 sensor I was wondering if I rewire the o2 sensor to the bung on the cat if it would stop from having cel problems. I have replaced my o2 sensor 4 times now and am about ready to re-wire it because now I'm not even sure if the wire is working since I unplug the o2 sensor and it does the same thing. Won’t turn on till I run it around 3k for a little bit. Anyway thanks for the help.

anyone? cant do it today since its raining :(

id get a new gasket, only because u shouldnt re-use gaskets, but yes, with the gasket in place, just bolt it up.

is the bung on the inlet side or the outlet side? If its on the inlet then yea, you can move it there if you want. why not test the o2 sensor to see if its working right, and if its not then rewire it. and you could just plug the bung on the cat if you want to leave it on your manifold.

the gaskit came with the cat it was a new gaskit but it has metal plates not a gaskit i have ever seen before. anyway the bung is on the inlet so ill probably move it. how do test my o2 sensor? if it needs to be rewired ill just rewire it. thanks!

exaust gaskets are metal gaskets. Use it and it'll work fine

ok now i have a problem i get ready to do it and first i cant fit my socket wrench on top to remove the top bolt and i cant even budge the other two they are all black and looks like they are rusted but got really hot or something. any ideas to make this easy?