It's much louder without cats. If you have a loud cat back already then you might not even like it without cats. It tends to make everything more raspy. I bought a mild cat back with the plan to yank the cats... and I'm happy with how it came out.

 

X2 Its MUCH louder with out cats. I agree.....if you already have a loud exhaust.....you'll probably blow the local cops out of their cars when you drive by.

 

I've got it after I went to an ORY, especially at idle, I think it's probably due to also going bigger injectors and I'm still waiting on my new tune. at idle, my AFR is usually pretty rich 12.5-13, sometimes dipping as low as 11.5 during a cold startup before the O2's kick in

 

it has a little deeper sound with the new setup. A little louder but not much at all. I love the way it sounds. It sounds more free. It was a good welcome difference in power from my SOTP dyno.