My exhaust sounds like its leaking (raspy airy noise) and the two reasons are the i have 2 flex pipes and they both suck, on my old exhaust i didn't have a flew pip at all, and the second reason is that i have a test pipe on the car too. Is there any way i can remove one of the flew pipes with some sort of piping, and will getting a hi flow cat help quieten down the sound. The exhaust is so loud that when cruising at 3-4k my windshield starts to vibrate and its incredibly annoying. Also underneath my car it smells like gas, its coming from my exhaust, is the reason for this b/c i don't have a rear o2 sensor and my ecu/fmu is pumping more fuel. any help would be great thanks