Exhaust Question: Y-pipe to CAT connection?

[chris070780]

I cut off my exhaust just after where the CAT bolts to the collection Y pipe. The bolts where very rusted and wouldn’t come off. After I cut, it exposed two pipes. One pipe inside another. The O2 sensor that is in front of the coupling looks to be going inside this inner pipe. My question is once I torch the bolts out does the O2 sensor have to be removed before the coupler will separate from the Y? I plan on just welding it back to the CAT and installing new bolts

 

[Anime]

You'll probably need to remove the oxygen sensor before the pipes will seperate.

I'd say cut off the bolts on the nut side, since you've mauled the pipe anyway you can do whatever you need to for them to break off, then you should be able to get the rest of the cat pipe off, and pound out the bolt studs on the Y-pipe side. Put in new studs, or just get regular bolts with locknuts, throw on a new converter and gasket and you're good.