Volkswagen could face renewed wrath from investors and the public after regulators in California found emissions-cheating software in some of the company’s Audi models. The California Air Resources Board (CARB) found evidence of emissions testing tampering in both diesel and gasoline engines, according to The Wall Street Journal. The software obscured accurate levels of carbon dioxide emissions, an environmentally harmful greenhouse gas.

VW found itself embroiled in a global emissions scandal in 2015 after investigators detected "defeat device" software in millions of the company’s diesel cars that had been marketed to consumers as low-emission "green" vehicles. The software made it look like the engines met emissions standards for nitrogen oxides, a smog-producing greenhouse gas. The German automaker was forced to shell out $14.7 billion in settlements with car owners and states (in addition to a $2.7 billion contribution to an environmental trust) in the US alone, making it the largest civil settlement in automaker history.

CARB’s findings indicate that similar "defeat device" software was installed in an unknown number of Audi cars that run on gasoline and diesel, but instead of masking levels of NOx the software obscured accurate levels of CO2 emissions, which contribute to global warming. CARB technicians demonstrated deviation in emissions standards by conducting tests in lab versus road conditions. The Audi software made it appear as though the cars emitted low levels of CO2 when operating in the lab, but the vehicles actually released amounts of CO2 that were much higher when the vehicles were made to react as though they were driving on the road.

The new discovery has not been publicly confirmed by Volkswagen or American regulators. The company was just nearing the end of its multi-billion dollar settlement and expects to start buying back vehicles from affected owners in mid-November. Volkswagen declined to comment when contacted by The Verge.

Part of Volkswagen's new official strategy to rebuild trust with the public and investors in wake of last year's scandal has been a plan to build 30 battery-powered electric cars over the course of the next decade. Volkswagen also invested $300 million in ride-sharing service Gett in June and Audi has been working toward creating self-driving technology for over 10 years. Nevertheless, people might not soon forget the missteps of a company that once made an internal powerpoint presentation on how to cheat emissions tests.