I suspect my 2002 ZO6 is running rich at 6000 feet altitude (Colorado Springs). On my 98 C5 I could adjust the fuel pressure to reduce the fuel to air ratio. I understand the 2002 will recalibrate to a 14.6 F/A ratio but this is probably a "volume" ratio. The problem at high altitude is although the F/A ratio may be optimized, the oxygen available is 20% less than sea level. I added a HallTech T-1 and noticed a "big" difference...but still suspect I am not seeing the performance the sea level guys are. Is there any way to manually adjust the F/A for altitude?