well, got the car about week and a half ago, it already had a mbc in it, i think its hallman, but idk....i recently bought a boost gauge and after drivin it was already set to 26 psi, i read the forums and saw 18 - 21 is stock...so i turned it down to 20 and tested, all was well.....all of a sudden few days later it was back up to 25 again, i turned it down, and again it went up....is mbc bad?

 

You could have a cut in one of the vaccum lines on the MBC that goes to the wastegate or a bad connection. Also take off the end nipple of the MBC with a wrench and remove the ball and spring and clean it.

 

yea one of the lines goes to the waiste gage, the other i belive to the IM

 

it seems to hold boost and its controllable....as far as the boost gauge shows