Summit sells hi-flow cats for like $70 i think. I agree on having at least one small Cat. It gives the exhaust a smoother tone on our rigs.. they sound kinda rough without them. I had gutted both Cats once and it was loud as hell with my 3a ricer muffler. Then I put a new OE pre-cat on it it sounded much better and quieter. Then decided I didn't like the ricer sound and went to Mach1 Muffler and they replaced my stock muffler with a flowmaster knockoff. It has no label on it so I don't know what it is. But it looks just like a flowie.. The sound is perfect in my opinion. Same sound it has in my videos. Alot of the noise my kia put out in the vids was coming from my ram air intake while I was 50% or more throttle.