When I step on the gas, there's a "SSSSHHH" sound (almost like the opposite of sucking in air) but when I'm around 3500 rpm and up, that's when there's the sucking in air sound. I followed the COBB instructions and everything fits well (I double checked). Just wondering if the early/temporary "SSSSHHH" sound is normal, or if anyone else is experiencing it. Improved throttle response is definitely there. Thanks.