Not all BOV's are the same. I have the Greddy Type-S right now. It leaks at idle, so the idle is a bit erratic. You can either recirculate the BOV to remedy this or buy an HKS SSQV which stays shut at idle. If I would have had more money when buying a BOV, I would have bought the HKS, but I went with the cheaper Greddy. Still sounds good though.