2003 Z71 Engine Brake

I just recently purchased a 2003 Z71 and it came with dual exhaust. When I go down hills, foot off of the gas, the engine sounds like it is governing itself down, like it's not free rolling. I don't know much about all of these kinds of things but would like to learn more. Someone suggested that the engine might have an engine brake on it. Can this be turned off? I don't think there have been any modifications done to the engine like a supercharger, but like I said, I don't know much. Any and all help would be appreciated. My wife and I both own chevy's and wouldn't own anything else! rspatz38538.4200115741

if your engine has a engine brake then no it cant be turned off it will have to be removed if you do not like this option,a engine brake is a unit to slow down the vehicle when towing a heavy load, otherwise pretty useless.