Intake Charge Pressure Control System Check

After the diagnostic trouble code of MFI system is read, turn off the ignition switch.
Disconnect the hose (black) from the turbocharger wastegate actuator control boost nipple at the air outlet fitting and plug this nipple.
Connect a hand vacuum pump to the hose (black).
Use the vacuum pump to apply negative pressure, and check the negative pressure condition while the engine is stopped and while it is idling.

Fig 1: Connecting Hand Vacuum Pump To Hose (Black)
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

NOTE: If this check indicates an abnormal condition, the turbocharger wastegate solenoid, the turbocharger wastegate actuator, or the hose is broken.

Fig 2: Identifying Negative Pressure Conditions
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.