i have had the ms for a few months now and it seems like i have pulled 20% from the 15-17psi area and smaller amounts averywhere. i could tune it perfect and the car is very happy but a few weeks later it seems to be running rich or lean and needs to be retuned. is there a fix or does everyone have to deal with this?

During part throttle MS is using the O2 sensor to take out a little fuel or add some as the weather changes. When you go into open loop mode and the ECU no longer adjust your fuel you could start to run rich/lean if the weather has changed alot. So as it gets colder the intake temps should drop some and you may have to add some fuel at WOT.

You need to alter your air charge temp correction values. The MS code notoriously over-corrects, so you'll see very rich in cooler weather and usually very lean in hot weather. Also make sure your sensors settings are correct, as this will intensify the effect. EasyTherm is the best way, IMO

i don't have an o2 sensor wired to the ms and ego has no athority. when it gets warmer it get rich and when i go to lower elevations it gets crazy rich. my iat sensor died and sinse then it seems to be very consistant. is the air charge settings the really confusing ones? i think i was checkin all that out and decided to leave it alone cause the notes told me to. lol