This sound started when I put my headers on. When accelerating at 2200-3000 rpm a clanging or banging sound comes from the exhaust. It gets louder as I go up and stops right at 3000. The car does not shake, bump, or anything else, and the performance is not affected. It is just annoying. I have been driving with this for about 3 months now hopefully going away. It does it in all gears. No smoke, no nothing--just annoying sound. My friends and I checked it out several times and just concluded that it was the header. Any other suggestions? Thanks.