An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »


MotorScience and Chi Zheng Clean Air Act Settlement

(Washington, DC – August 29, 2013) Two Los Angeles-based consulting firms, MotorScience Inc., and MotorScience Enterprise Inc., (MotorScience) and their owner, Chi Zheng, have agreed to settle alleged Clean Air Act (CAA) violations stemming from the illegal import of 24,478 all-terrain, recreational vehicles into the U.S. from China without testing to ensure emissions would meet applicable limits on harmful air pollution, announced the U.S. Environmental Protection Agency (EPA), the Department of Justice, and the California Air Resources Board (ARB).

MotorScience and Zheng have agreed to have a stipulated judgment entered against them for a $3.55 million civil penalty and to pay an additional $60,000 civil penalty within six months. The United States will receive 80 percent of collected penalties, and California will receive the remaining 20 percent.

On this page:

Overview of Defendants

MotorScience is a California corporation formed in 2006 with its principal place of business near Los Angeles, California. Chi Zheng is the president of MotorScience. MotorScience provides consulting services which enable its clients to import and sell vehicles and engines in the United States. A person may not sell or import vehicles and engines into the Unites States unless that vehicle is covered by an EPA-issued certificate of conformity (COC). Rather than handling the application process itself, an importer or manufacturer may hire a company like MotorScience to test its vehicles and prepare its application for submittal to EPA’s Office of Transportation and Air Quality (OTAQ). When OTAQ approves an application, MotorScience’s client becomes the COC-holder.

MotorScience has submitted hundreds of COC applications on behalf of numerous companies, most of which are based in the People’s Republic of China. It was one of the leading firms of its kind when the recreational vehicle COC requirement came into effect in 2006. Millions of vehicles have been imported into the United States under COCs obtained from applications prepared by MotorScience.

Top of Page


The EPA began investigating MotorScience and Mr. Zheng in 2008. The investigation revealed that MotorScience used the emission test results from one vehicle for countless dissimilar others by misrepresenting the vehicle’s type, manufacturer, and components. By improperly using test results in this manner, MotorScience avoided actually testing the emissions of the vehicles for which it sought COCs, undermining the fundamental purpose of the EPA’s vehicle certification program. MotorScience also neglected to keep vital records that are central to adequate administration and enforcement of the program.

In 2010, OTAQ voided 12 COCs based in part on the false information submitted by MotorScience and Chi Zheng, acting for its clients. Voiding a COC renders all vehicles purportedly covered by that COC to be uncertified, and therefore illegal for sale in the United States.

In September 2011, the United States initiated the enforcement case in the United States District Court for the Central District of California that is resolved by this settlement. The United States alleged that MotorScience and Mr. Zheng caused its clients to import uncertified vehicles and to fail in their recordkeeping obligations under the Clean Air Act.

Top of Page

Injunctive Relief

Defendants must either entirely cease, or follow a compliance plan for, all activity concerning nonroad vehicles and nonroad engines regulated under Title II of the Clean Air Act for 15 years. This compliance plan is detailed in the consent decree. Defendants must also notify the United States and California of any other business activity under the mobile source provisions of the Clean Air Act. 

Top of Page

Pollutant Reductions

The United States alleges that Defendants’ violations arise from their failure to actually test the emissions of the vehicles at issue in this case. As such, the United States lacks emission data and the emission consequences of the alleged violations are not clear. However, limited testing of affected vehicles showed significant exceedances of applicable emission standards for hydrocarbons and oxides of nitrogen.

Top of Page

Health Effects and Environmental Benefits

The Clean Air Act aims to reduce emissions from mobile sources of air pollution, including carbon monoxide, oxides of nitrogen, and hydrocarbons, which are harmful to human and environmental health. Mobile sources is a term used to describe a wide variety of vehicles, engines, and equipment that generate air pollution and that move, or can be moved, from place to place. Mobile sources of air pollution contribute approximately 73% of the nation’s carbon monoxide emissions and 58% of the nation’s oxides of nitrogen emissions.

The EPA runs a vehicle and engine certification program under the Clean Air Act to ensure that every vehicle and engine sold or imported into the United States conforms in all material respects to a vehicle or engine that has been proven to meet applicable emission standards. To obtain a COC, the party seeking the COC must apply for one according to the following procedure. First, the applicant must group vehicles and engines into engine families—sets of engines expected to have similar emission characteristics throughout their useful life. Second, the applicant must conduct emission tests on a representative vehicle or engine (an emission-data vehicle or EDV) to demonstrate that the vehicles or engines in the engine family, once built, will comply with the exhaust emission standards. Third, the applicant must prepare a complete and accurate application for certification. In this application, the applicant must, among many other requirements, describe the engine family’s basic design and emission controls, identify all model names included in the engine family, provide emission data, and describe the EDV. Finally, the applicant must submit the application and necessary fees to OTAQ, which then reviews the application to determine whether to issue a COC for the engine family for that model year. If, on its face, the application appears to satisfy all necessary requirements, OTAQ issues a COC.

Here, the settlement requires that Defendants follow—for 15 years—a compliance plan to ensure that emissions testing and certification applications submitted to the EPA accurately represent the nonroad vehicles and engines that will be sold in the United States under the COC. Nonroad vehicles and engines includes recreational vehicles, generators, lawn and garden equipment, and other internal combustion engines. This will ensure that nonroad vehicles and engines used in the United States meet or exceed the emission standards for harmful air pollutants.

Top of Page

Civil Penalty

MotorScience and Mr. Zheng have agreed to pay a $60,000 civil penalty within 6 months, and to have a stipulated judgment entered against them for an additional $3.55 million civil penalty. The United States will receive eighty percent of collected penalties, and California will receive the remaining 20 percent.

Top of Page

Comment Period

The proposed settlement, lodged in the United States District Court for the Central District of California, is subject to a 30-day public comment period and final court approval. Information on submitting comment is available at the Department of Justice website.

Top of Page

For more information, contact:

Evan M. Belser, Attorney Adviser
Air Enforcement Division
Office of Civil Enforcement
Office of Enforcement and Compliance Assurance
United States Environmental Protection Agency
1200 Pennsylvania Avenue
Washington, D.C. 20460
Evan Belser (

Top of Page