U.S. to begin re-testing all diesel cars for pollution-cheating devices after VW scandal

The U.S. government said Friday it will begin re-testing diesel cars from all manufacturers to detect pollution-cheating devices like the one Volkswagen used to circumvent emissions tests.

The U.S. Environmental Protection Agency (EPA) said in a statement it has sent a letter to vehicle manufacturers notifying them that the agency is "adding to its confirmatory testing additional evaluations designed to look for potential defeat devices."

Last Friday, the EPA sent a Notice of Violation of the Clean Air Act to Volkswagen, alleging that four-cylinder Volkswagen and Audi diesel cars from model years 2009-2015 include defeat devices that circumvents EPA emissions standards.

According to the agency, the device turns off emissions controls when the car is driving normally, and turns them on when the car is undergoing an emission test. This results in cars that meet emissions standards in the laboratory or testing station, but during normal operation, emit nitrogen oxides at up to 40 times the standard.

The EPA initially identified the problem in nearly 500,000 diesel cars sold in the United States since 2008. But Volkswagen later admitted the devices were installed in 11 million diesel cars. Enditem