Originally Posted by
zooby
why are MBC and BOV bad for stock wrx? just curious and lazy to search if you kno plz pass the info

As far as the MBC goes, It gets really technical. I know it has something to do with Closed and Open loop. I just cant remember off the top of my head.
And the BOV is bad because you car runs lean when the housing opens to dump air. This has been known to stall teh car or even cause engine problems.
But all of this stuff is debated online over and over. I am just giving you my opinion.
- Mike