I have been undesided on what combo I am going to run, this the reason I have not put a tuner and exhaust yet. I am ready to get rid of this dpf and get some mileage. Most of the video's ive listened to the 5" mbrp and quad have a bad hiss which I think sounds like SHIT!! I have seen one with magnaflow and it did not have the hiss??? Please let me know which combo will not give the hiss and just a good tone, doesnt need to be loud and im not interested in gauges, as they will not sell me on a tuner. Just looking for mileage and 4'' exhuast with good sound, thanks for the info.