The U.S. Environmental Protection Agency (EPA) has determined the 3.0-liter V6 diesel engine used by Volkswagen is also equipped with a defeat device.

Over 10,000 vehicles in the U.S. have been found to use illegal software on their V6 diesel engines, adding onto the number of Volkswagen and Audi vehicles equipped with the illegal 2.0-liter diesel engine. The EPA issued a notice of violation to Volkswagen, Audi and Porsche saying that the 2014 Volkswagen Touareg, 2015 Porsche Cayenne and 2016 Audi A6 Quattro, A7 Quattro, A8, A8L and Q5 are all in violation. There is also an unknown number of 2016 model year vehicles that are involved.

SEE ALSO: European Commission Provisionally Approves Real World Diesel Emission Testing

The defeat device on the V6 engines were discovered through EPA’s joint testing initiative with the California Air Resources Board (CARB) to determine what other vehicles are equipped with defeat devices that allow them to cheat on EPA diesel emissions tests. The two agencies plan on testing all light-duty diesel vehicles currently on sale for defeat devices and it’s unclear if any other automakers will be found guilty.

In addition, the 3.0-liter V6 engines were also found to have one or more “Auxiliary Emission Control Devices” that the Volkswagen Group failed to disclose to EPA as required by law.

This article originally appeared at