Just hours after federal and state regulators accused Volkswagen of using so-called “defeat devices” on newer model cars in order to ensure they passed emissions tests, the carmaker said the allegations aren’t true and that it will continue to allow sales of the recently identified automobiles. 

Officials with VW say the devices found on nearly 10,000 model year 2014 to 2016 VW, Porsche and Audi vehicles equipped with 3.0-liter diesel engines is within the bounds of Environmental Protection Agency standards, the Wall Street Journal reports.

On Monday, the EPA and California Air Resources Board announced that further testing of VW-branded vehicles detected defeat devices in the 2014 VW Touareg, the 2015 Porsche Cayenne, and the 2016 Audi A6 Quattro, A7 Quattro, A8, A8L, and Q5.

According to the EPA notice of violation [PDF], the vehicles contain two modes of operation – temperature conditioning and normal mode.

As with the 482,000 vehicles previously identified by the agencies, the new models also contain a “sophisticated software algorithm” that can detect when the car is undergoing official emissions testing, and to only turn on full emissions control systems – the temperature conditioning mode – during that testing.

The effectiveness of these vehicles’ pollution emissions control devices is greatly reduced during all normal driving situations, emitting nearly 40 times the allowable standard of nitrogen oxide.

A spokesperson for VW disputed the accusations, saying the automaker didn’t install emissions-test evading software on any of the newly identified vehicles, the WSJ reports.

“It is a permissible software. What’s at issue here is clear: Does the U.S. want competition in the American market or not?” the spokesperson said, noting that the company would not halt sales on the 2014 to 2016 vehicles.

The carmaker is cooperating with the EPA and CARB, saying that senior engineers are working with the agencies to “clarify things.”

Regulators reminded VW on Monday that it is illegal to manufacture, sell or offer for sale a vehicle with a defeat device.

Under the Clean Air Act, vehicle manufacturers are required to certify to the EPA that their products will meet applicable federal emission standards to control air pollution, and every vehicle sold in the U.S. must be covered by an EPA-issued certificate of conformity.

Motor vehicles – such as the Volkswagen models in question – equipped with defeat devices, which reduce the effectiveness of the emission control system during normal driving conditions, cannot be certified. However, regulators assured owners that the vehicles are safe to drive.

EPA, Volkswagen Spar Over New Emissions Claims [The Wall Street Journal]

Want more consumer news? Visit our parent organization, Consumer Reports, for the latest on scams, recalls, and other consumer issues.