i have ssac headers and when i put my car in reverse it sounds like something is rubbing it vibrates my car and makes a loud noise. is this my downpipe hitting the sway bar? if so how do i fix it? Its soo annoying also my car vibrates a lot when in drive and idling when stopped. is this being caused by the downpipe too? if i raise my rpms to just under 1000 it goes away. (i know its not sc coupler too.) how can i fix this