Hi guys, I bought this Civic a month ago and started putting on some basic bolt ons. So far I put on a ebay short ram with velocity stack and sounds great. I just put in some stainless steel DC headers this morning and noticed this kind of "zzz" sound when accelerating. I'm asking this because I have read that headers shouldn't change the sound of the car unless you have an exhaust system, but mines is stock. At idle the car sounds normal, only when I'm giving the car gas it makes that "zzz". I checked for leaks and didn't smell any fumes or anything funky. So is this sound normal after installing headers?