What's the difference between standard and high altitude? The car I'm trying to get has the high altitude emissions. Around here the DA is 4000ft+ nearly all the time, will the car run rich or throw codes? I've got a kick-ass deal on this car, they're giving me $1300 at the place the dealer gets work done at their cost because they can't find one like I want with the Mach1000, just the Mach460. Thanks guys