So I just had catless downpipes and a stage 2 tune installed on my car. The sound is amazing but I am getting this rattle/flapping/jack hammer type noise when pushing the car hard - basically in high RPMs or full throttle. Have any of you had experience with this? I know the downpipes make the car more raspy but during hard acceleration it seems like something is flapping or the sound waves are too much for the exhaust? I’m used to the usual AMG sound of the 63s but this is different and only had peak RPMs.

Would adding high flow cats or x pipe help or did you guys find something touching/vibrating/flapping? Any help is greatly appreciated as I need to pinpoint the problem and fix it. Not sure if the video actually lets you hear the sound at peak RPM which is more of a piece from the cutout (fake) exhaust tips flapping or something else.

It does sound awesome - don’t get me wrong I do love it! But you don’t hear that flapping like sound in the higher rpms? You hear the normal AMG sound but behind that is the other sound that may not be normal for a cat less AMG?