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Press Release

PPEI and President Kory Willis Plead Guilty and Agree to Pay $3.1 Million in Criminal Fines and Civil Penalties for the Manufacture and Sale of Illegal Delete Devices and Tunes for Diesel Trucks

For Immediate Release
U.S. Attorney's Office, Eastern District of California

Louisiana-based company Power Performance Enterprises Inc. (PPEI) and its President and owner, Kory B. Willis, pleaded guilty to criminal charges today in federal court in Sacramento, California. Both defendants pleaded guilty to conspiracy to violate the Clean Air Act and to violating the Clean Air Act by tampering with the monitoring devices of emissions control systems of diesel trucks. 

In addition to the criminal charges, the United States also filed a civil complaint against PPEI and Willis today in federal court in the Western District of Louisiana, alleging violations of the Clean Air Act’s prohibition against the sale or manufacture of devices that bypass, defeat, or render inoperative emissions controls. Under the criminal plea agreements and a proposed civil consent decree, PPEI and Willis agreed to pay a total of $3.1 million in criminal fines and civil penalties. Under the civil settlement, both Willis and the company agree not to manufacture, sell or install any device that defeats emissions controls.

“The manufacture and sale of illegal delete devices and tunes such as the ones targeted by today’s actions put at risk decades of progress in controlling harmful pollution from motor vehicles in this country,” said Assistant Attorney General Todd Kim of the Justice Department’s Environment and Natural Resources Division. “As the plea agreements and civil settlement show, we will vigorously enforce the prohibitions on delete devices and tunes, using all appropriate enforcement tools.” 

“The defendants sold products nationwide that allowed drivers to illegally tamper with emissions controls in a manner that caused dramatic increases in emissions,” said U.S. Attorney Phillip A. Talbert for the Eastern District of California. “Environmental laws that control diesel pollution protect the environment and the health of the general public and are especially important to protect sensitive populations such as the young, the elderly, and people who suffer from respiratory conditions. Thanks to the work of the EPA, these guilty pleas will send a message to the delete device industry that disregarding federal environmental laws will result in federal charges. The U.S. Attorney’s Office will continue to vigorously prosecute those who place profit above the public’s health and the environment.” 

“The actions of Power Performance Enterprises Inc. and its President and owner, Kory B. Willis, that advanced them to the top of the delete tuning market have caused and will continue to cause the emissions of dangerous compounds into the environment which could contribute to serious health issues,” said U.S. Attorney Brandon B. Brown for the Western District of Louisiana. “This proposed civil settlement sends a clear message that these types of violations will not be tolerated and those who violate these environmental laws will be held accountable.”

“EPA estimates that the defeat devices illegally sold by the defendants are expected to cause the release of over 100 million pounds of excess air pollutants over the life of the diesel trucks in which they were installed,” said Acting Assistant Administrator Larry Starfield for EPA’s Office of Enforcement and Compliance Assurance. “This case clearly demonstrates the negative environmental impact of defeat devices and EPA’s commitment to vigorously enforcing laws designed to protect public health and the environment.” 

According to court documents, from PPEI’s incorporation in 2009 until 2019, PPEI and Willis were among the nation’s most prominent developers of custom software known as “tunes,” and in particular, “delete tunes.” Generally, tunes can alter a diesel truck’s fuel delivery, power parameters and emissions. PPEI and Willis were well known for their custom delete tunes, software which allows a “deleted” truck to appear to run normally. A deleted vehicle is one that has had emissions controls removed or disabled, resulting in vastly increased emissions of air pollution.

Willis and PPEI reached the top of the illegal delete tuning market, tuning over 175,000 vehicles according to Willis. Willis also stated that PPEI was the biggest custom tuning company in the world, had over 100,000 customers, and tuned more than 500 vehicles a week. According to internal PPEI records, PPEI typically sold well over $1 million dollars of product a month. According to EPA calculations of the estimated emissions impact, PPEI’s sales of delete tunes between 2013 and 2018 alone are anticipated to cause over 100 million excess pounds of nitrogen oxides (NOx) emissions over the life of the diesel trucks equipped with those products.  

Deleting a diesel truck causes its emissions to increase dramatically. For example, for a fully deleted truck, which has had all emissions equipment removed or disabled, EPA testing quantified the increased emissions as follows: NOx increased 310 times, non-methane hydrocarbons increased 1,400 times, carbon monoxide increased 120 times, and particulate matter increased 40 times. EPA’s Air Enforcement Division released a report in November 2020 finding that more than half a million diesel pickup trucks in the United States — approximately 15% of U.S. diesel trucks that were originally certified with emissions controls — have been illegally deleted. 

Diesel emissions include multiple hazardous compounds and harm human health and the environment. Diesel emissions have been found to cause and worsen respiratory ailments such as asthma and lung cancer. One study indicated that 21,000 American deaths annually are attributable to diesel particulate matter. Exposure to polluted air in utero also has been associated with a host of problems with lifelong ramifications including low birth weight, preterm birth, autism, brain/memory disorders and asthma.

Under the proposed civil settlement, defendants PPEI and Willis will pay $1,550,000 in civil penalties and agree not to manufacture, sell, or install any device that bypasses, defeats, or renders inoperative motor vehicle emissions controls. The defendants will not sell or transfer the intellectual property associated with these products, and will destroy illegal products still in inventory, cease warranty support for previously sold products, revise marketing materials, notify customers and dealers of the law and the settlement, and train employees and contractors. According to civil court documents, Willis and PPEI halted sales of specified delete devices in the fall of 2019 following enforcement activity by EPA. 

The defendants are scheduled to be sentenced in the criminal case by U.S. District Judge John A. Mendez on Aug. 23. Willis faces a maximum statutory penalty of five years of incarceration on the conspiracy count, two years of incarceration on the tampering count, and for each count a maximum fine of $250,000 or twice the gross pecuniary gain derived from the offense. PPEI faces for each count a maximum fine of $500,000 or twice the gross pecuniary gain derived from the offense. Under the plea agreements, the defendants agree to jointly and severally pay a $1,550,000 criminal fine. The sentences will be determined at the discretion of the court after consideration of all applicable statutory factors and the Federal Sentencing Guidelines, which take into account a number of variables.

The criminal case was the product of an investigation by the EPA’s Criminal Investigation Division. Assistant U.S. Attorney Katherine T. Lydon of the Eastern District of California and Senior Counsel Krishna S. Dighe and Trial Attorney Stephen J. Foster of the Environmental Crimes Section of the Department of Justice’s Environment and Natural Resources Division (ENRD) are prosecuting the criminal case. The federal civil case is being handled by Senior Counsel Nicole Veilleux of the Environmental Enforcement Section of ENRD and Attorney-Advisor Ed Kulschinsky of the Air Enforcement Division of the EPA.

Stopping the manufacture, sale and installation of illegal delete devices 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 Louisiana and is subject to a 30-day public comment period and final court approval. A copy of the decree, and information on submitting comments will be available on the Department of Justice website at:  

Updated March 15, 2022