If you dont want to spend the $$ on a custom map job, you can always just download the map specific to your brand of exhaust from powercommander.com. Ive heard the results are pretty good, while not as "perfect" or dialed in as a custom map. Some people just want some sound from a new pipe and all they need is to match the fuel curve to the new pipe a little better than just leaving it stock. Ive got a custom map, though, and i will say it IS sweet. The driveability sucked on my bike with D and D pipes before the PCIIIusb was installed.