I put my Borla Atak cat back on myself and was wondering if I should have it welded, my mechanic said that as long as everything is tightened properly that there should be no problems. I know that there is a small hole in the can for draining, so if you’re experiencing a leak from there I wouldn’t think it’d be a problem, I’ve had no leaks from the joints that I’m aware of after 15k miles with it on, so you may just need to snug things up a bit. I’m no expert, just figured I’d give my two cents worth. Sent from my iPhone using Tapatalk