I bought #4165 in Broomfield, CO and both the window sticker and the emissions certification sticker mention this. Anybody (Mr.T) know what this is all about and if it includes or excludes any parts? I'm guessing its in the software and the EPA allows emissions from high altitude certified vehicles to be a little dirtier to make up for power loss. As I understand it, high altitude vehicles do not meet Kalifornia of Federal emissions standards.