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Press Release

Flo~Pro Performance Exhaust and Thunder Diesel & Performance Company to Halt Sales of Illegal Vehicle Emission Control Defeat Devices and Pay a $1.6 Million Penalty

For Immediate Release
Office of Public Affairs

Red Deer Exhaust Inc. (doing business as Flo~Pro Performance Exhaust) and Thunder Diesel & Performance Company have agreed to stop selling devices that bypass or disable vehicle emissions control systems, and pay a $1.6 million penalty, to resolve allegations that they violated the Clean Air Act (CAA).  

The complaint, filed simultaneously with the consent decree, alleges that the parts described above are “defeat devices” prohibited by the CAA. The Environmental Protection Agency (EPA) estimates that prior to its 2018 investigation, Flo~Pro manufactured or sold more than 100,000 aftermarket defeat devices in the United States per year. In early 2019, Flo~Pro suspended sales of the defeat devices in the United States in an effort to resolve this matter.

“Defeat devices violate Clean Air Act emissions requirements meant to protect public health and the environment, as well as vulnerable communities that are disproportionately impacted by air pollution,” said Assistant Attorney General Todd Kim of the Justice Department’s Environment and Natural Resources Division (ENRD). “This settlement ensures that Flo~Pro will stop the sale of all defeat devices in the United States and is the latest reminder that the Department of Justice will hold the aftermarket automotive parts industry accountable for violations of federal anti-pollution laws.”

“The exhaust from diesel pickup trucks equipped to operate without essential emissions controls causes severe harm to our nation’s air quality,” said Acting Assistant Administrator Larry Starfield for EPA’s Office of Enforcement and Compliance Assurance. “This action will stop the manufacture and sale of these illegal products, preventing additional excess pollution caused by aftermarket defeat devices and keeping the air we breathe clean.”

Under the agreement, Flo~Pro, an automotive parts manufacturer based in Alberta, Canada, has agreed to stop manufacturing and selling parts for diesel pickup trucks in the United States, that bypass, defeat or render inoperative EPA-approved emission controls and harm air quality. Thunder Diesel, a distributor based in Mountain Home, Arkansas, has shut down its operations and is no longer selling auto parts. The companies will pay a $1.6 million penalty, which is a reduced amount due to verified financial information indicating the companies’ limited ability to pay. The companies will notify customers who purchased subject parts that the products violate the CAA, will no longer provide technical support or honor warranty claims for the products and will provide CAA compliance training for employees.

This settlement will improve public health and prevent substantial amounts of air pollution in the future, as the installation of defeat devices prevents emission controls from working properly. Tampering with diesel-powered vehicles by installing defeat devices causes large amounts of nitrogen oxide and particulate matter emissions, both of which contribute to serious public health problems. These include premature death, aggravation of respiratory and cardiovascular disease, aggravation of existing asthma, acute respiratory symptoms, chronic bronchitis and decreased lung function. Numerous studies also link diesel exhaust to increased incidence of lung cancer. Respiratory issues disproportionately affect families, especially children, living in underserved communities overburdened by pollution. EPA estimates that the subject parts from these companies in 2016-2019 may have resulted in more than 775 million pounds of excess nitrogen oxides emissions and 6.7 million pounds of excess particulate matter over the life of the affected vehicles. Stopping the sale and use of defeat devices will help reduce harmful air pollution that exacerbates the health effects of pollutant exposures. 

Stopping the manufacture, sale and installation of defeat devices on vehicles and engines used on public roads as well as on nonroad vehicles and engines is a priority for EPA. To learn more, visit:

The consent decree for this settlement was lodged in the U.S. District Court for the Western District of Arkansas and will be open for public comments for a period of 30 days.

If you suspect someone is manufacturing, selling or installing illegal defeat devices, or is tampering with emission controls, tell the EPA by writing to

Updated July 29, 2022

Press Release Number: 22-812