[mrguyorama]

You can ban modifying your car to pollute more (which we do) without banning modifying your car.

This isn't complicated FFS.

The difficulty against this in the US is the unfortunate reality that the people coming to these shops to enable their stupid trucks to roll coal are the people who should technically be raiding and shutting down these companies. This can be fixed.

Physically, you can already modify your car to be controlled by a stupid program and that has been possible since at least the 90s. You can do the supposed harm by not being aware of damage to your exhaust system.

The solution to exhaust harms of ICE engines is electric cars, not a reduction in consumer rights.

[vablings]

The EPA heavily regulates any emissions defeat devices. The problem is they spend most of their time going after tuner shops where most cars run on ethanol rather than diesel shops who cater to brain-damaged customers who think rolling coal is "cool"

[darkwater]

In Spain (but I think in every EU country) you must go through legal inspection and certification if you do modify your car. And most of the aftermarket mods people install are totally illegal and would not pass that exam. I mean changes like putting a spoiler, lowering the height from ground etc