B16 woes

I have an interesting problem with my car that just started yesterday. Every time I start to accelerate there's like a hissing sound (it almost sounds like a very muffled BOV sound) the only problem is my car is NA! The motor is basically stock except for a CTR n1 pulley(no a/c, no P/s, but it's genuine honda so it should be a good part right?) and then an exedy clutch and flywheel. It's been ididling kind of erratically at stopsigns lately and then this problem just started yesterday. I don't think the headgasket is blown or anything like that because the last time I really pushed it was back in june @ LACR. What could it be? I'm totally stumped.