No it can't be adjusted, you can have a factory download to suit pipes and filter etc, but the bike will end up running lean anyway and you won't lose the decel popping. There is no real way to adjust the factory ECM.
Hi Scotty,
You could maybe contact Adelaide HOG and they could put out an e-mail to members. http://www.adelaidehogsa.asn.au/
(BTW I loaded the program 401 into my Tmax last night and altered my raw throttle pos'n. The idle is settling after a couple of cycles, and it felt good riding to work this morning. Thanks heaps for the help!)