More than a month after it first broke, Volkswagen's diesel emissions scandal is still growing: the latest to get roped in is a 3-liter diesel mill used in a variety of VW, Audi, and Porsche models. The EPA filed a notice of violation of the Clean Air Act today in reference to the engine, which the agency claims can produce nitrogen oxide emissions up to nine times over EPA limits. As with the 2-liter engine that first exposed Volkswagen's cheating, the 3-liter is claimed to have a "defeat device" that is designed to meet emissions only when the car detects that it is undergoing an official emissions test. Affected models include the 2014 Touareg, the 2015 Porsche Cayenne, and the 2016 Audi A6, A7, A8, A8L, and Q5.

The action affects a relatively small number of vehicles sold in the US — around 10,000, plus "an unknown volume of 2016" models — but it'll undoubtedly spread to Europe, where diesel sales are much higher. Volkswagen's recently installed CEO, Matthias Müller, recently said that fixes for the 2-liter engines would begin in January of next year, but it's unclear whether they'll be able to fix the 3-liter engines as well — or whether even more cheating engines are yet to be exposed.

The EPA noted in its release that today's notice of violation was made possible by more stringent emissions checks that have been imposed since the first Volkswagen cheat was exposed. If other automakers have employed similar cheats — and it's entirely possible that they have, in order to sidestep ever-tightening emissions regulations — this is a sign that they may not be able to get away with it for much longer.