I have had a flowmaster with only one converter on my truck for about a year now. Well it has got louder and louder and started driving me nuts so i finally did something. The blowmaster wasnt rusted yet or anything so i didnt want to replace it ya know. so i added a supertrapp to the tail pipe and what a positive difference it made. much more tolerable now and my milage has went up a tinge due to the extra back pressure. I am running 12 discs on it now and will probably play with it to see how much quiter i can get it, but overall its a neat thing. $100 from summit.