BOV Leak?
 

ok whell i have a k&n filters on the car with the stock BOV hangen next to it...

ok so heres the story now...whell after leaving school and got on the high way i wanted to open the car up so i hit the gas and then after 4.5k rpm i hear like the bov just leaking/ blowing air.. and i looked at my gauge and it does a 10-8-10ish then drops to like 7... im guessing its a bov leak...

so how would i fix this?? or if im wrong whats the problem