Sorry to hear that. GM has a much longer warranty on emissions. I had a few heaters replaced under warranty. I was out of town on a trip when I had a def heater fail. I maxed out the miles just to get it to a dealer. $1000 later, I was back on the road. It failed 2 years later. I put a China made assembly in myself for $130. Knock on wood, it has lasted 20k miles longer than any of the OEM assemblies.I'm outside the warranty window at 39k miles and almost 4 years.