I installed jun downpipes with oem cat back. For the most part it sounds good. The issue I’m getting is if I load up the car around 2000rpm I’m getting the raspy rattle sound when the rpms come up. It doesn’t not happen very often but I sometimes hear it with windows down. I finally got a good video of it. There’s no picture but you can hear it good. Anyone have any ideas? It could be normal for downpipes with no cats or resonators and it’s just some rasp but I have never heard another stinger owner say anything about this sound. Any help would be great. I’ve had two shops have a look and they do not see any fitment or leak problems. It’s hard to pin down as I have to load it up while driving to make it do it. This video makes the sound stick out good as I drove with the door a bit open with my phone on the floor.