(Warning) pops and crackles tune

I've been hearing some people say pops and crackles are safe, ive ran stratified's loud p&c tune off and on for 2 years, been getting p420 code. Decided to replace the downpipe, looked inside the oem and saw that part of the honeycomb media had broken off the lower o2 sensor was also burnt up. So if you are deciding whether pops and crackles are for you be aware of the premature damage to the catalytic converter.