2006-2008 Polaris Snowmobiles FS/FST Service Manual., Page 86Get this manual
EFIIgnition Systems Boost Pressure Sensor Circuit (FST Only)
The boost pressure sensor is located on the boost box just before the throttle bodiesThe ECU uses this sensor to determine the actual absolute charged air pressure within the intake systemThe sensor is located on the FST's boost box underneath the fuel tankNOTE: Bosch PN 261 230 042 stamped on cover