Not running cats on a vehicle is a choice I cannot endorse. As others have noted it is irresponsible and bad for our air quality in general.
Imagine if everyone decided to do the same? Wonder what would happen? Want government inspections to come back? I sure don't.
Funny that in our fleet we have not replaced any cats in my memory. Even at 500k miles our last truck sold still had it's originals in place and working correctly.
The last time I replaced one was in a 1976 Dodge van where the screen blew out and the pellets clogged the muffler. I can only wonder what you folks are doing to ruin a converter, they are pretty hard to kill IME.
"In the United States it is a violation of Section 203(a)(3)(A) of the 1990 Clean Air Act for a vehicle repair shop to remove a converter from a vehicle, or cause a converter to be removed from a vehicle, except in order to replace it with another converter.,[26] and Section 203(a)(3)(B) makes it illegal for any person to sell or to install any part that would bypass, defeat, or render inoperative any emission control system, device, or design element."
Yep, we should all just disregard the laws and do whatever we want...