I just installed the MBRP 5 inch Turbo-Back and I went to go start up my truck and for the first 5 seconds or so it sounds great nice deep and throaty sound and then all of a sudden the deep and throaty sound goes away and if you walk around the the exhaust it sounds like its making almost a sucking sound. I am not sure if that is normal if that sound is just coming from the turbo or what. Everything is secure and I didn't find any leaks and it sounds great when it's being drove it only does it when its sitting at idle.