I just bought a 2006 Chevy C7500 with the 7.8L Duramax. It's my first Duramax, the engine sounds great, plenty of power (most of the time). At random times it will go into limp mode. Doesn't seem to matter if your on the highway or on country roads. It doesn't throw any codes either. I haven't taken it to the shop yet because I think it might be a loose connection? Someone said that it might be the knock sensor malfunctioning? I'm not sure where to start looking.
Any advice would be greatly appreciated.