Can someone clarify what the inside of a high flow cat looks like. If you hold one up to the light and try and look through from end to end what should you see? The reason I ask is my exhaust smells way rich and I'm not sure if mine is just a shell or it actually works. Mine has an Air tube and I can see it run straight across the diameter of the opening towards the middle of the cat. I can also see the entire diameter ofthe opening all the way through 100% with the exception of the mesh at each end. Did I get a crapper? thx