[temp8830]

But that's 95% of cars that didn't need to be tested. All that the testing requirement does is reinforce the (correct) public's perception that it's a free money scheme. If the "check engine" light is not on in a modern car it's pretty much good to go.

When cars do need an emissions related fix, it's almost always that little charcoal canister that people flood with gas because nobody told them why it's a bad idea to top off the tank after the first click.

[Retric]

> But that's 95% of cars that didn't need to be tested.

That would only be true if the government was aware of which cars were in the 95% ahead of time. The fact that so many cars fail means even the driver isn’t sure let alone the government.

Even cars significantly newer than the average age of cars on the road regularly fail the emissions tests without any obvious issues ahead of time. Which means without testing you don’t know which cars will pass.

[vel0city]

I've had a few cars fail emissions over the years and it was never because of the vapor. It was normally P0420 codes that weren't resolved from O2 sensors and other attempted fixes on 20 year old Hondas. Or fouled EGR airflow spaces needing cleaning. Or EGR/manifold baffles that would get stuck.