Oh yeah, I've still got cats and stock manifolds, But the sound is great. Its a deep, mellow tone. I was expecting a little louder, but I still love it.
Headers will be soon, but I will still run cats.
The craftsmanship on the headers and exhaust is the best I have ever seen. Hand welded, that looks better than some of the computer welded headers on the market.
I recommend the system to anyone!