question about my exhaust

right now I have stock cat and piping but I have installed a flowmaster super 44 on my 2002 jeep grand Cherokee 4.0l v6. I knew when I installed it that it wasn't going to be extremely loud but I thought it was going to be louder than it is now. so now I am contemplating whether I should get a new high-flow cat or if I should run "fake" duals . how does the exhaust sound if you have piping that splits from one to two pipes from the muffler and looks like duals on the back, can you tell a difference? what else will make my exhaust louder without removing my flowmaster? thanks in advance.