Intake Charge Pressure Control System Check

Disconnect the hose (black) from the turbocharger wastegate solenoid and connect a three way joint between the hose and the solenoid valve.
Connect a hand pump (pressurized type) to the three-way joint.

Fig 1: Checking Intake Charge Pressure Control System
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
Use the turbocharger wastegate actuator control boost nipple of air outlet fitting to disconnect the boost hose. Plug this nipple.
CAUTION: Do not apply the pressure of 94 kPa or more to prevent the diaphragm damage.

Applying a pressure with the hand pump, check tightness both when the hose end is closed and when it is open.

Fig 2: Locating Boost Hose With Turbocharger Wastegate Actuator

Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

ENGINE STATE AND NORMAL STATE REFERENCE CHART

Engine state	Hose end	Normal state
Stop (Ignition switch: ON position)	Opened	Pressure leaks.
Stop (Ignition switch: ON position)	Closed	Pressure is maintained.
Rapid racing	Closed	Pressure leaks.