It appears General Motors Corp. is the first auto manufacturer to feel the backlash brought on by the Volkswagen diesel scandal (noted as #Dieselgate on social media). The diesel variants of the Chevrolet Colorado and GMC Canyon were slated to hit dealers in the fourth quarter of this year, but it looks like that may be delayed.

According to Automotive News, the Environmental Protection Agency (EPA) will not certify GM’s newest diesel pickups until they are road- and lab-tested. The agency announced last week, in the wake of the VW scandal, more stringent lab and on-road testing is required to ensure vehicles will meet emission standards in all scenarios. The four-cylinder diesel, for mid-size pickups, has already been used in the global market, but it was not subject to some of the emissions gear U.S. standards require. General Motors Corp. is confident the Colorado and Canyon diesels will pass the additional testing.