I currently have a testpipe on my 00 civic si with the greddy evo cat-back exhaust. I was wondering if i put a high flow cat, will it be a little more quieter? or maybe reduce or remove the raspy/rice sound i hate.... when i had this exhaust on my sohc 95 ex it was deeper with no rasp sound... in other words i want to elimate that raspy sound... any suggestions