I just installed a Megan Racing Stainless Steel Header on my 01 Civic Coupe. There is a screw/bolt that you can take off or leave on. Does anyone know what this is for? I do know that if I take it off the header is louder than if I leave the screw/bolt on. Also I notice if I do remove it, when I give it gas it gives a ticking sound. Does anyone know what that ticking sound could be?