The PCIII leaves no trace of itself in the ECM when removed. It simply overides or fools the ECM into doing what it wants it to do...the ECM still functions normally, and no trace is detectable if a dealer hooks up to the ECM. From my understanding, the dealers can't even read the base map installed at the factory, but can read any changes made by a SERT or Digital Tech download, which funtions as an "overlay" to the stock ECM programming. As mentioned by Jerry above, the PCIII fools the ECM into thinking it's in open loop all the time and runs off the PC map. As hd-dude mentioned, Fuelmotousa is about the best place to get one, and Jamie will load a map for your set up that will get you up and running...I got a map installed for my SE slips...worked well, bike ran good, but a bit on the rich side, so the fuel milage dropped. When I put the Rineharts on, Jamie e-mailed me a map for that set-up and it ran fine too, but I wanted it dialed in, so got a tune. Both maps provided by Jamie worked well, they were just a little on the rich side...better to err on that side than let things remain too lean.
My 2 cents...