Which of the laws or regulations that apply to diesel vehicles and pollutants emitted do your mechanical engineer friends object to the loudest? Up here where

Which of the laws or regulations that apply to diesel vehicles and pollutants emitted do your mechanical engineer friends object to the loudest? Up here where I live there are many diesel pickup trucks that have been EGR deleted and several local businesses sprang up just to serve that community. It was very common and still is common to be driving down the highway behind a truck that suddenly rolls thick black smoke on everything around it. Many of these trucks aren't driven by mechanical engineers as I suspect there is a small, insignificant population of that particular specialty locally. They are driven by young, dumbass children or inbred rednecks who bought the libertarian/fascist line about needing to own some libs or the line about the government needing to get out of people's lives and let everyone do whatever they want. One day they will get their due. Instead of going after the shops that sell this bullshit, regulators need to use the traffic cameras and license plate scanners on every highway in Texas to build a database of vehicles and go after individual owners and businesses who sell and tune equipment or remove exhaust components. Maximize the fines and confiscate the vehicles until the owner pays for the vehicle to be brought back into compliance or back to OEM specs. Then require them all to have monthly inspections at their own expense for at least two years to verify that the vehicle remains compliant. I've probably just made a couple of dumb suggestions in this post but these coal-rolling assholes piss me off.