The EPA recently called out Volkswagen's 3-liter diesel for emitting up to nine times the federal standards for nitrogen oxides, alleging that it has a "defeat device" — the same kind of cheat that had first nabbed VW with its smaller 2-liter diesels in September. Volkswagen quickly rebutted, claiming that the 3-liter engines weren't cheating emissions tests. Now, it's pulling every car from the US market that uses those engines anyway.

Affected cars include the Volkswagen Touareg, Porsche Cayenne, and a variety of Audis from the A6, A7, A8, and Q5 lines over three model years, up to and including 2016. The company says that the stop-sale doesn't mean the cars are cheating, WSJ reports, but that it's reviewing the EPA's data to figure out what's going on.

Volkswagen's 2-liter diesel, which is offered in a variety of high-volume models like the Golf and Jetta, was already pulled from dealers' stock but hasn't yet been brought back to market; Volkswagen claims that a new emissions control system in the 2016 versions of those engines is not a cheat, but the EPA hasn't yet approved them for sale. It's unclear how long the 3-liter diesels will be off the market — but considering that VW isn't budging on its position that there is no cheat affecting these engines, it could take a while to resolve the impasse.