It’s not just from a repair shop standpoint “any person to sell, offer for sale, advertise, or install any new aftermarket catalytic converter” that means that individuals can’t do it either (any person is also in the “used” section too). And that doesn’t say anything about inspections, but it could be somewhere else I just read what you linked, so the fines aren’t for inspections (unless it’s somewhere else and says the same…this isn’t legal advice so go fuck urself if you read this and do something dumb lol).