I've been reading up since it was brought up. From what I read Rubi is correct. The previous versions of DPM used inputs to their on-board computer (ECU) such as engine RPM, throttle position, air temperature, engine water temperature and, on Summit models, ambient (barometric) pressure to determine the proper pressure to be applied to the float bowls for proper fueling. The newer systems have added a knock sensor which is crucial for fine tuning and running any motor on the ragged edge of power\efficiency and detonation. But the problem is there is no airflow sensor, which still says that a person should rejet if they ever put pipes on there DPM equipped sleds, however a sinlge pipe maybe such a little change that it wouldn't matter, but for my own piece of mind I would still rejet.
2005 Ski-Doo 600 H.O.