There are two distinctive chirping sounds I noticed when installing true duals. One is the sound of the exhaust going through the small holes of the baffles. The only way I have found to get rid of that sound is to wrap the baffle. I have used steel wool and / or baffle wrapping material. The other sound is more to the front of the motor and may have more to do with back pressure and/or enrichening the fuel mixture from the original exhaust mufflers. Taking my 2 1/5" D & D slip-ons off and putting back on the original mufflers, the chirp goes away. Hope this helps.