does the MAP sensor on my truck read psia or psig? The TST box at altitude where I live and work 5400-6000 feet doesnt start fueling at 2-3 psi like it does at sea level, it's more like 6-7, which leads me to think it reads psia. If so, I'd like to wire a dial potentiometer or even a 3-4 position switch with different resistors corresponding to the voltage I'd like to see going into the map sensor reading of the TST depending on whether I'm at my parents house close to sea level, in denver at 5300ft or up in the mountains at varying higher altitudes. I'm just not sure what resistors to get... or what range I'm looking for.

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does the MAP sensor on my truck read psia or psig? The TST box at altitude where I live and work 5400-6000 feet doesnt start fueling at 2-3 psi like it does at sea level, it's more like 6-7, which leads me to think it reads psia. If so, I'd like to wire a dial potentiometer or even a 3-4 position switch with different resistors corresponding to the voltage I'd like to see going into the map sensor reading of the TST depending on whether I'm at my parents house close to sea level, in denver at 5300ft or up in the mountains at varying higher altitudes. I'm just not sure what resistors to get... or what range I'm looking for.

I think I may have confused myself and put psig where I meant psia and vice versa. Either way, found out it's most likely not possible

More than likely your going to end up making a mess out of it. Since boost level is very dynamic and change rapidly putting a fixed resistor in the line is either going to pull it down too low or push it up too high. Boost pressure under 5 PSI give the most for MPG numbers. As you push the boost up you start to lose timing advancement. This why the smoke switch back in the day failed so badly because fooling for a extremely high boost number typically gave the most retarded timing possible making the truck very doggy on sluggish.