i wouldn't advise running test pipe on the street or daily but it is the best in my book for the strip, and yea a gutted cat wont give you the straight through flow of a test pipe, it also sounds raspy, my stock one was clogged, gutted it for a while, then bought random, i have a test pipe as well but it stinks so bad, thought i would be a smarty and just gut half the stock one and get half the filterage of the stock one,no good, the catalyst broke completly up then worried me about blowing threw and clogging the muff.