Your freedom of choice stops when you start harming others by removing pollution control devices. When people do that on diesel vehicles they significantly increase ozone and particulate pollution that cause health problems for children (especially childhood asthma), the elderly, and others with respiratory problems. Even functioning normally these vehicles emit more of these pollutants so frankly I’m not a fan of people using them wastefully, though I won’t dispute they have a right to currently. What makes me angry is the lack of consequences when these owners flout the law and remove legally mandated pollution control devices without regard for the harm they are causing others.