UPDATE: In light of the EPA’s allegations that more Volkswagen Group models were discovered with software to hide emissions levels from regulations, Porsche Cars North America issued a voluntary stop-sale order on models allegedly affected by the latest issue. They are the model year 2014 through 2016 Cayenne Diesel SUVs.

The Volkswagen Group's diesel emissions cheating scandal has expanded to include more models from Audi and even a Porsche. Late yesterday, the Environmental Protection Agency issued the German automaker with a notice of violation for a 3.0-liter V-6 diesel engine used in several models from VW and Audi as well as Porsche’s Cayenne.

The affected models include the 2014 Volkswagen Touareg TDI, the 2015 Porsche Cayenne Diesel and the 2016 Audi Q5, A6, A7 and A8 TDI models. They were all determined to have the same “defeat device” software that bypasses emission controls when the car is on the road and are emitting nitrogen-oxide emissions at rates of up to nine times the allowed standard, according to the EPA.

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About 10,000 of the vehicles are affected in the United States and the extent of the problem outside the country is yet to be determined. Note, this is on top of the 482,000 VW and Audi models in the U.S. and more than 11 million vehicles worldwide that were previously announced to have been fitted with the defeat device software.

2016 Audi A6 4-door Sedan quattro 3.0L TDI Prestige Engine

2016 Audi A6 4-door Sedan quattro 3.0L TDI Prestige Engine

As Green Car Reports points out, unsold 2015 and 2016 vehicles will likely be subject to an immediate stop-sale order, meaning dealerships will have to take both new and used models off sale until a fix can be developed—a process that is unlikely to be readied until sometime next year. Furthermore, VW may be faced with as much as $375 million in fines in the U.S. on top of what it is already facing.

Furthermore, if the EPA’s latest allegations are accurate, it casts doubts on VW’s past statements about the emissions cheating scandal and how many vehicles are actually affected. However, the automaker said in a statement that no software had been installed on the 3.0-liter V-6 diesel engine in question to alter emissions characteristics in a forbidden manner and that it is fully cooperating with the EPA. In a separate statement, Porsche said it was surprised by the allegations and is also cooperating fully with all relevant authorities.

VW is still in the process of developing a fix for engines previously announced to be affected by the emissions cheating scandal. Once a fix is developed, it still needs to be tested and approved before it can be installed which is why the first recalls aren’t likely to be implemented until January 2016. The first recall has already been announced, though, and affects 8.5 million vehicles across 28 European nations.

To keep track of our past coverage on VW's emissions cheating scandal, head to our Volkswagen news hub.

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