Fuel Tank Differential Pressure Sensor Check

Tumble the second seat.
Remove the service hole cover (upper) and packing.
Remove the service hole cover (lower) and packing.
Disconnect the harness connector.

Fig 1: Removing Service Hole Cover (Fuel Tank Differential Pressure Sensor)
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
Disconnect the fuel tank differential pressure sensor connector and connect special tool MB991348 between the terminals of the disconnected connector.
Turn the ignition switch to "ON" and take a reading of between terminals (2) and (3).
1. Standard value: 2.0 - 3.0 V
  
  Fig 2: Checking Fuel Tank Differential Pressure Sensor
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.