Exactly. Years back, I moved to California with an 80's sports car that was admittedly quite hotrodded, but I made very sure that the hotrodding did not worsen its emissions because 1. I wanted to keep driving the car in CA and 2. I don't want to pollute. First SMOG test in CA, the car blew clean as a whistle. It met emissions standards 40 years harsher than it ever had to meet.
Except I had all sorts of aftermarket parts in there from years of repairs, none of them with the all-important California CARB seal of approval on them, so even though it blew clean, it still "failed emissions" and I had to sell it to someone out of state. I'm still bitter about it.
In Ohio in the early 2000s all us kids were removing cats and passing the sniffer test easily. There was a visual test so we would normally just hollow out the existing cats. A lot of times cars with missing cats would pass the visual as well.
Except I had all sorts of aftermarket parts in there from years of repairs, none of them with the all-important California CARB seal of approval on them, so even though it blew clean, it still "failed emissions" and I had to sell it to someone out of state. I'm still bitter about it.