8_Porsche_Macan_S_DieselThe Environmental Protection Agency (EPA) has revealed that other diesel engines may be affected by the Volkswagen emissions scandal after finding evidence of a defeat device on 3.0-litre TDI Audi, Porsche and Volkswagen models.

The defeat device “increases emissions of nitrogen oxide (NOx) up to nine times EPA’s standard,” says the U.S. agency – which has issued a second notice of violation of the Clean Air Act to Volkswagen AG.

The EPA states the following models are affected:

  • 2014 Volkswagen Touareg
  • 2015 Porsche Cayenne
  • 2016 Audi A6 quattro, A7 quattro, A8, A8L, Q5

“VW has once again failed its obligation to comply with the law that protects clean air for all Americans,” said the EPA’s Cynthia Giles.

The latest violations affect around 10,000 cars sold since the 2014 model year, plus “an unknown volume of 2016 models”.

Volkswagen has since released a statement denying the allegations. The firm said it “wishes to emphasise that no software has been installed in the 3-litre V6 diesel power units to alter emissions characteristics in a forbidden manner”.

Random testing

The latest Volkswagen Group Clean Air Act violation was discovered during a randomised screening process of U.S. diesel cars conducted by the California Air Resources Board.

“These tests have raised serious concerns about the presence of defeat devices on additional VW, Audi and Porsche vehicles,’ said CARB executive officer Richard Corey.

“This is a very serious public health matter. ARB and EPA will continue to conduct a rigorous investigation that includes testing more vehicles until all of the facts are out in the open.”

The first notice of violation was issued to Volkswagen AG by the EPA on 18 September, after it discovered the presence of emissions test cheat code that caps NOx emissions during official testing – but lets vehicles emit up to 40 times the legal limit during on-road use.

The EA 189 2.0-litre TDI is the engine in question.

Since then, Volkswagen’s share price has plummeted as the firm has found 11 million vehicles worldwide contain defeat device coding.