Porsche now finds itself under the spotlight of German regulators for possibly using a defeat device on their gas models. German publication Wirtschafts Woche reports that Germany’s Transport Ministry and Federal Motor Transport Authority (KBA) were tipped off by people close to Porsche about possible cheating on emissions tests. According to the story, some Porsche vehicles have software that can detect when they are on a dynamometer (or rolling road) based on whether or not there the steering wheel was turned. If this sounds familiar, that's because Audi is accused using something similar on some of their models.
Porsche has responded to the questions about this and said the software is used detect steering movements is to improve the overall driving experience and not to fool emission tests. In a statement to Bloomberg, Porsche said it is cooperating with the investigation.