A Nashville-based automotive aftermarket parts distributor is set to pay $320,000 in civil penalties for selling illegal defeat devices that disable vehicle emission controls, violating the Clean Air Act (CAA).

The U.S. Department of Justice and the Environmental Protection Agency (EPA) announced Dec. 10 that Diesel Performance Parts (DPPI) will notify dealers and customers about the settlement and remove all marketing materials promoting these devices.

The DOJ said that since September 2018, DPPI sold at least 6,858 defeat devices designed to bypass emissions control systems in diesel-powered vehicles and engines.

“Defeat devices violate the Clean Air Act and cause a vehicle to contribute significantly higher amounts of pollutants into the air,” the Justice Department’s Environment and Natural Resources Division Assistant Attorney General Todd Kim said. “Excess emissions tangibly worsen the air we breathe. We are committed to upholding the rule of law.”

An EPA study showed that aftermarket defeat devices lead to excess emissions of nitrogen oxides and particulate matter, contributing to severe health issues like asthma, chronic bronchitis and lung cancer.

“These illegal practices contribute to harmful air pollution and impede federal, state and local efforts to implement air quality standards that protect public health,” EPA Acting Regional Administrator Jeaneanne Gettle for Region 4 added. “Emissions from mobile sources play an important role in EPA’s Southeastern region, and the use of these defeat devices hampers our ability to maintain compliance with the National Ambient Air Quality Standards.”