Vehicle exhaust modifications are a double-edged sword. In addition to excessive noise, some modifications — also known as “tampering” — can also degrade air quality.
Tampering with a vehicle’s emissions control system is illegal under the Clean Air Act (CAA) and causes excess emissions of nitrogen oxides (NOx), particulate matter (PM), and other pollutants to the air we breathe. The CAA also prohibits manufacturing, selling, offering for sale and installing aftermarket devices which effectively defeat those controls.
Tampering can cause a vehicle to emit hundreds to thousands of times more pollution than it otherwise would. Recent EPA investigations indicate that controls on over 500,000 diesel pickup trucks, or about 13% of those registered that were originally certified with emissions controls, have been fully removed or deleted through tampering. The excess NOx emissions from these vehicles is the equivalent of adding 9 million trucks to our roads.
A “full delete” of the emission controls on a modern heavy-duty diesel pickup truck can cause it to emit as much harmful pollution as 300 trucks with fully functioning emissions controls! Tampering with only some components also leads to significantly elevated emissions of NOx, PM, carbon monoxide, and hydrocarbons.
These pollutants contribute to a variety of public health problems, such as premature death in people with heart or lung disease, heart attacks, irregular heartbeat, aggravated asthma, decreased lung function, and respiratory symptoms such as irritation of the airways, coughing, or difficulty breathing. NOx reacts with sunlight to cause ground-level ozone pollution (smog), so visibility, discomfort and illness may increase in the summer, when people enjoy being outside and traffic increases with travel to vacation and recreation areas.
How can I report suspected tampering to EPA?
Email tampering@epa.gov
Or use the form at https://echo.epa.gov/report-environmental-violations