When I put my Leo Vince exhaust on my bike I got a idle surge, turned up the idle and it got better. It still surges a little bit, about when the bike gets to 120*F or so, but then as soon as I start riding and it gets good heat in it the surge goes away. I am going to try a couple things and have it dyno tuned and see if that will help. BTW, no idle surge with the db killers installed.