Actually, I think theres a rust hole in it . I'm not sure since its blocked by the heat sheild or what ever the metal thing is blocking it. some time I'll pull that off and have a look. I put on a cat back about 3 months ago and I remember there being rust on the cat and header. A few days ago a friends dad looked at my car and said there was an exhaust leak near the header, so I assume there is a rust hole.