July 1: So it begins. Don't worry, this is not in the correct legal jurisdiction!
EVAP Control System Pressure Sensor
WARNING: This page is about a different car, the 2011 Infiniti M56. However, it is still accessible from the selected car via links, so may be relevant.
The EVAP control system pressure sensor detects pressure in the purge line. The sensor output voltage to the ECM increases as pressure increases.
Fig 1: EVAP Control System Pressure Sensor Voltage / Pressure Graph