Porsche has launched an internal investigation into past gasoline engines over the possibility of "manipulations" in the and .
German publication Bild am Sonntag first reported the news Sunday and Porsche confirmed the internal probe with Roadshow.
"Porsche is routinely and continuously reviewing technical and regulatory aspects of its vehicles. The company also conducts reviews of potential issues. This is an expression of a functioning system of internal control measures and our corporate culture," a spokesperson said in a statement.
Details surrounding what the "manipulations" entail aren't available, though language suggests there may be emissions issues afoot. Porsche merely said in reviews such as this, the focus is often on "specific hard-ware and software used in certification testing."
"In certain cases such components may also have differed from parts used in series vehicles," the statement added.
The carmaker underscored this investigation does not pertain to vehicles currently in production.
Numerous automakers have come under scrutiny sincespilled into the public domain. In the past, Porsche also in Germany after authorities discovered the company used Audi engines with defeat devices installed. The automaker continues to work with authorities as it proceeds with this most recent probe.