Quote Originally Posted by axa View Post
How does drilling out the at help? does it restrict airflow?
are you litterally just removing the catalyst inside?
Take a flashlight and get down on your knees and look up the muffler. The catalytic converter is in the front of the muffler. Yes, you are removing the catalytic guts. I used a one inch bimetal hole saw with a 12 inch extension and did a slow cut. I was lucky this time and all the guts blew out when I started her up. When I did it on my long gone 2010 I has to take the muffler off and run a snake from the front of the pipe to get all the pieces out.

Warning:The exhaust note is going to be a lot louder. Nothing like a Harley loud but...

Doing this gets rid of that real hot spot in the front of the muffler. That cat puts out some heat.