We’re still in the earliest days of the Volkswagen “Dieselgate” saga, but so far we know that as many as 11 million vehicles built by VW and its subsidiaries are affected by the software cheat. The damage done to Volkswagen is hard to quantify just yet, but the ripples of this scandal are already being felt by other automakers as the EPA seeks to crack down on emissions cheats.

Among the first to be affected is General Motors, with executives telling Automotive News that the upcoming Chevy Colorado and GMC Canyon models with the 2.8-liter diesel engine could be delayed by new on-road emissions tests by the EPA.

“The EPA and CARB told us they are going to do on-road testing,” Chevrolet Trucks assistant chief engineer Scott Yackley told AN. The diesel truck twins will not receive EPA certification until additional on-road testing has been completed, assuring the government agency that other automakers aren’t trying to cheat the system. The Colorado and Canyon were scheduled to launch in the 4th quarter of 2015, and GM doesn’t know just how much of a delay the extra testing could cause.

GM already offers the 2.8-liter diesel motor outside of the U.S., but minus the onerous Selective Catalytic Reduction urea injection system required to meet EPA emissions standards. Rated at 181 hp and 369 lb-ft of torque, this four-cylinder diesel is GM’s answer to increasing fuel economy requirements. Official MPG numbers are still pending, but the diesel motor is expected to exceed 30 mpg on the highway, rivaling the Ram 1500 EcoDiesel for the pickup efficiency crown.

That is, if they pass the EPA’s new certification process.