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U.S. EPA settles with three Southern California companies for selling pollution control bypass equipment

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Nahal Mogharabi (

LOS ANGELES – Today, the U.S. Environmental Protection Agency (EPA) announced settlements with three Southern California automotive parts manufacturers for violations of the Clean Air Act. The companies sold or distributed aftermarket auto parts known as defeat devices which bypass or render inoperative required emissions control systems. The three firms will pay a total of $322,000 in penalties.

“Region 9 will continue to focus on companies selling consumer devices that disable emission controls on their cars and trucks,” said EPA Pacific Southwest Regional Administrator Mike Stoker. “These controls are an important tool for reducing pollution, particularly in parts of the Pacific Southwest which struggle with poor air quality.”

Cars and trucks manufactured today emit far less pollution than older vehicles. This is made possible through careful engine calibrations and the use of filters and catalytic converters in the exhaust system. Aftermarket defeat devices bypass these controls and cause vehicles to emit higher levels of emissions. EPA testing has shown that defeat devices can increase a vehicle’s NOx emissions substantially.

Today’s announcement highlights three separate administrative settlement agreements:

Yoshimura Research and Development of America, Inc. manufactured and sold 46,502 aftermarket exhaust systems for motorcycles from 2008-2010 which required the removal of catalytic converters. The company, located in Chino, California, paid a reduced penalty of $225,000 due to financial hardship., Inc. sold 16 aftermarket exhaust systems for motor vehicles from 2015-2016 that required the removal of catalytic converters. The company, located in La Habra, California, paid a $7,000 penalty.

Two Brothers Racing, Inc. manufactured and sold 13,597 various exhaust systems for motorcycles from 2013-2016 that required the removal of catalytic converters. The company, located in Santa Ana, California will pay a reduced penalty of $90,000 penalty due to financial hardship.

NOx pollution contributes to the formation of harmful smog and soot. Children, older adults, people who are active outdoors (including outdoor workers), and people with heart or lung disease are particularly at risk for health effects related to smog or soot exposure. Nitrogen dioxide formed by NOx emissions can aggravate respiratory diseases, particularly asthma, and may also contribute to asthma development in children.

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

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