RedLined

Can anyone with hp tuners or a scanning tool do me a favor and check to see if theyre map and barometric sensors read the same at key on, engine off? Mine don't match but ive read a few posts where people have said map always reads 100kpa which doesn't make sense to me because I thought map and baro sensors should be the same at key on, engine off. My baro reads 97.25 kpa and map is 101 kpa.