Volkswagen CEO Martin Winterkorn, in a statement released by the automobile manufacturer on Sept. 20, apologized for breaking the trust of the company's customers over the software that has been designed to provide false emissions data for some of its vehicles.

The company will be stopping sales in the United States of the 2015 diesel vehicles that are involved in the emissions test cheating debacle, in addition to ordering an external investigation to cover the matter.

The Environmental Protection Agency recently discovered over 480,000 cars made by Volkswagen that were outfitted with "sophisticated software algorithm" to trick emissions tests into thinking that the cars were not releasing massive amounts of nitrogen oxide.

The software reduces the emissions output of the vehicles, but in reality, the cars were releasing nitrogen oxides that were more than 40 times compared to the standard levels. The software switched emissions controls off for normal driving conditions and then turns them on while the vehicles undergo emissions testing.

According to the agency, Volkswagen could be facing fines of as much as $18 billion for the usage of the software.

"We do not and will not tolerate violations of any kind of our internal rules or of the law," Winterkorn said in the statement, adding that the company is in full cooperation with the agencies on the investigation into the matter.

Volkswagen spokesman John Schilling said that the German company would be stopping sales for 2015 and 2016 Volkswagen and Audi vehicles that come equipped with 4-cylinder turbo diesel engines, which the car company has been marketing as "clean diesel." In addition, Volkswagen will be stopping sales of used vehicles that are powered by the engine.

A representative for Volkswagen confirmed that there will be a partial stoppage of the sales of the affected cars, but no numbers were revealed.

According to Bernstein analysts, the emissions cheating issue that Volkswagen is currently embroiled in is very serious, as it is much worse than the usual recall orders, calibration errors or safety flaws.

Kelley Blue Brook analyst Karl Brauer said that Volkswagen has been leading the pack in the United States in offering diesel cars that had performance similar to gasoline vehicles.

"Now, we have to wonder if the technology really advanced as far as we thought at VW," said Brauer, adding that while the company found a good mix of economy, performance and durability, it could not have the diesel engines achieve emissions levels below the regulations.