[81MC]

Because it forces the hand of small number of people, and does very little at all for everyone else.

If an emissions test is reasonable enough to not be unduly prohibitive, the vast majority of vehicles on the road would pass - a notion supported by BC when they cancelled their AirCare program and Ontario when they stopped testing tailpipe emissions.

In Ontario for example, all they do now is scan for DTCs. That isn’t going to stop anyone ‘Rollin coal’. But it may push someone with a perfectly fine vehicle to send it to scrap and lease a new hunk of #### they can’t afford because they don’t have 3K to fox something that may or may not even be related to excessive emissions. There is a reason ‘cash for clunkers’ programs exist everywhere emissions testing is standard - those who fail are more likely to be in an economic position where $1000 cash and a 20% car loan is easy to accept than a few thousand dollar repair bill. The other group that would fail is the hobby/enthusiast crowd, which I believe has as much right to their activity as anyone else.

According to the EPA, personal transportation accounts for less than 20% of ghg emissions. If the 95% figure is accurate, that’s a remarkably low potential benefit at best. And that’s assuming the vehicle gets repaired, not disposed of.

If you want to improve air quality, look at things that are cheaper to implement, less burdensome on the economically marginalized, and that actually have a real impact.
Let’s start with wood fireplaces, stoves, and camp fires - it’s not even debatable that the emissions from a chimney are FAR worse than any modern vehicle. You’d get a much greater benefit at far less expense by simply banning wood burning within city limits, for example.