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News Releases from HeadquartersEnforcement and Compliance Assurance (OECA)

EPA Highlights Enforcement Actions Against Those Who Violate the Defeat Device and Tampering Prohibitions under the Clean Air Act

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WASHINGTON (April 30, 2020) — The U.S. Environmental Protection Agency (EPA) has identified numerous companies and individuals who have manufactured and sold both hardware and software specifically designed to defeat required emissions controls on vehicles and engines used on public roads as well as on nonroad vehicles and engines.

Cars and trucks manufactured today emit far less pollution than older vehicles. This occurs through careful engine calibrations and emissions controls in exhaust systems such as catalytic converters and diesel oxidation catalysts. Aftermarket defeat devices bypass these controls and cause higher emissions. EPA testing has shown that these devices can increase vehicle emissions substantially. Illegally modified vehicles and engines contribute substantial excess pollution that harms public health and impedes efforts by EPA, tribes, states, and local agencies to plan for and attain air quality standards.

In an on-going effort to address this air quality problem, EPA has resolved more than 50 cases addressing these types of violations since 2015. Today’s announcement highlights three such cases that have been resolved administratively:

  • Freedom Performance, LLC was a major web-based distributor of diesel defeat device products. On February 24, 2020, EPA’s Chief Administrative Law Judge (ALJ) issued a default judgment against Freedom Performance, LLC, ordering a $7.058 million penalty for 13,928 violations of the aftermarket defeat device prohibition of the Clean Air Act (CAA).
  • Spartan Diesel was ordered to pay a $4.1 million penalty for 5,000 violations of the aftermarket defeat device prohibition of the CAA on October 30, 2018, by the ALJ.
  • KT Performance is a Florida-based company that sold and installed approximately 2,833 delete products for diesel-powered trucks between January 2013 and April 2018. EPA filed an administrative complaint against KT Performance for violations of the aftermarket defeat device and tampering prohibitions of the CAA on April 30, 2018. The parties resolved the matter on July 3, 2018. The company was assessed a civil penalty of $52,284 that was calculated based on a demonstrated inability to pay a higher amount.

For examples of similar civil judicial settlements, see EPA’s recent settlements with Performance Diesel, Inc.Punch It Performance  , and Derive Systems. To view all closed vehicle and engine enforcement matters, please visit:

In recognition of the substantial excess pollution caused by illegally modified vehicles and engines, EPA is implementing a National Compliance Initiative entitled Stopping Aftermarket Defeat Devices for Vehicles and Engines. In furtherance of this initiative, EPA will continue to vigorously pursue enforcement against those who violate the defeat device and tampering prohibitions of the Clean Air Act. In addition, EPA has and will continue to prosecute criminal activity related to the illegal sale and installation of defeat devices.

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