Very common indeed. I have the leaking issue. Fitment is good.. No cut anywhere. Def, call them. They should be able to help you out.. If you have access to compressed air tank available, i would plug up all port and collector, then fillit with air.. Look for leak, get some soap and water to spray around the weld. No bubble no leak, for the moment atleast. Cant say for future after couple thousand miles.. Good luck.