Alright, I have a b16 a block, p30 pistons and a p72 head with a venom intake manifold, stock injectors, stock throttle body. There is a very loud high pitched squealing noise, and i dont know where its coming from. i am positive that its vacuum related, because when I shut off the car, the squeal will slowly die away, directly as the needle on the vacuum gauge drops, and when it hits 0, the noise is gone. i cant seem to find it, i replaced the IM gasket, applied hondabond when I put it on, and i replaced the injector seals, throttle body gasket. Also, when I'm driving, if i am in say 3rd gear going slow, i can hear the noise (because it's in vacuum) and when i floor it (now vac gauge shows 0) the noise is gone.