Volkswagens sit in a Chicago dealership lot Sept. 18, 2015. The EPA has accused Volkswagen of installing software on nearly 500,000 diesel cars in the U.S. to evade federal emissions regulations. Scott Olson/Getty Images

Following accusations by the Environmental Protection Agency that Volkswagen used sophisticated devices on cars to cheat emissions tests, Consumer Reports has pulled its endorsement of two VW cars. The decision by a publication that many car-buying customers regard as a bible comes as Volkswagen faces more than $18 billion in potential regulatory fines.

Consumer Reports said it has suspended its "recommended" rating for the Jetta diesel and the Passat diesel until it can "retest these vehicles with a recall repair performed," according to a statement posted online. "Once the emissions systems are functioning properly, we will assess whether the repair has adversely affected performance or fuel economy."

The EPA Friday issued Volkswagen a "notice of violation," alleging that the company used a so-called "defeat device" -- software running in certain VW and Audi diesel models -- to get around Clean Air Act requirements. The software can detect when a car is undergoing emissions testing, allowing VW vehicles to meet standards during testing but then emit pollutants up to 40 times the standard during normal driving, the EPA said.

The alleged violations cover approximately 482,000 cars sold in the U.S. since 2008, including the Jetta, Beetle, Audi A3 and Golf -- all with model years 2009 -15 -- as well as the Passat for model years 2014-15.

While the EPA can require manufacturers to recall vehicles that don't meet emissions standards, the agency said that Volkswagen is not yet facing a recall, Reuters reported. The violations cited "do not present a safety hazard, and the cars remain legal to drive and resell," the agency said in a press release.

The Clean Air Act violations could cost Volkswagen as much as $37,500 per car.