Not familiar with rules in other states, but NY state requires each and every motor vehicle to get a safety inspection and be tested on a dynomometer tester for excessive fuel emissions. The fist year of a new car gets a waiver on the emissions test
And you guys think California is strict? You can drive a smoker with the bumper zip tied on and a door missing around here. No tests ever, except at a sale for smog. Some crazy counties might test. You might get a few random safety check roadblocks. Or sobriety.
Basically we have too many cars to set up a test infrastructure, and too many goof balls that would never show up, or could not.