Volkswagen halts sales of Audi models after EPA accusation

Nathan Bomey | USA TODAY

Show Caption Hide Caption VW scandal spreads to gasoline-powered cars The Volkswagen scandal is widening as the company says it has found faulty emissions readings for the first time in gasoline-powered cars. Meanwhile, its Porsche unit is halting some sales of models criticized by U.S. regulators. Bloomberg

German automaker Volkswagen has halted sales of certain Audi luxury models after the U.S. Environmental Protection Agency accused the vehicles of violating emissions standards.

The stop-sale order issued to U.S. dealers covers 3-liter, 6-cylinder diesel versions of the 2015-16 Audi A6, A7, A8 and Q5, as well as certified pre-owned models. Those plush vehicles are among the most profitable for Volkswagen.

The parent company has also stopped sales on the 3-liter diesel versions of the 2015-16 Volkswagen Touareg and the 2014-16 Porsche Cayenne.

The EPA and California Air Resources Board on Monday alleged that Volkswagen had installed illegal software on these models to evade U.S. standards on nitrogen oxide emissions. The automaker quickly issued a statement denying that accusation.

Audi spokesman Brad Stertz said in an interview Wednesday that the company is "trying to work with EPA and CARB to show our emission results and understand how they came to their conclusion."

Regulators said the company used a "defeat device" to trick regulators into believing that the cars are compliant, when in fact the vehicles are emitting harmful pollutants at rates of up to nine times the acceptable limit.

Volkswagen had admitted installing similar software on up to 11 million vehicles worldwide in September, triggering a massive regulatory crisis involving numerous government investigations and lawsuits and potentially costing tens of billions of dollars.

But the company rebuffed EPA's fresh allegations regarding the Audi models, the Porsche Cayenne and the VW Touareg, saying in a statement Monday that it would "clarify this matter" for the EPA.

Cynthia Giles, assistant administrator for EPA's Office of Enforcement and Compliance Assurance, told reporters on Monday that the agency has "clear evidence of these additional violations."

Follow USA TODAY reporter Nathan Bomey on Twitter @NathanBomey.