LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Subaru >> 2020 >> WRX STI >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Fuel Injection System (2.5L) >> Intake Manifold >> Installation
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Intake Manifold: Installation

  1. Install the intake manifold onto cylinder heads.
    NOTE: Use a new gasket.

    Tightening torque: 

    25 N.m (2.5 kgf-m, 18.4 ft-lb)

    G08538655Courtesy of SUBARU OF AMERICA, INC.
  2. Connect the fuel delivery hose, fuel return hose, and evaporation hose.
    G13639991Courtesy of SUBARU OF AMERICA, INC.
  3. Fix the engine harness to the rocker cover LH with the air duct.

    Tightening torque: 

    6.4 N.m (0.7 kgf-m, 4.7 ft-lb)

    G08538653Courtesy of SUBARU OF AMERICA, INC.
  4. Fix the engine harness to the rocker cover RH with clips (A).
    G06344566Courtesy of SUBARU OF AMERICA, INC.
  5. Lift up the vehicle.
  6. Connect connector (A) to the exhaust camshaft position sensor, connector (B) to the exhaust oil flow control solenoid valve, connector (C) to the ignition coil.
    G08538651Courtesy of SUBARU OF AMERICA, INC.
  7. Install the engine harness cover. (Right side only)

    Tightening torque: 

    5 N.m (0.5 kgf-m, 3.7 ft-lb)

    G06344564Courtesy of SUBARU OF AMERICA, INC.
  8. Install the clip securing the engine harness. (Left side only)
    G10264720Courtesy of SUBARU OF AMERICA, INC.
  9. Lower the vehicle.
  10. Connect the connector to the intake oil flow control solenoid valve.
    G06344563Courtesy of SUBARU OF AMERICA, INC.
  11. Connect the connector to the intake camshaft position sensor.
    G06344562Courtesy of SUBARU OF AMERICA, INC.
  12. Connect the connector to the secondary air combination valve.
    G06344561Courtesy of SUBARU OF AMERICA, INC.
  13. Connect the connector to the knock sensor.
    G06344560Courtesy of SUBARU OF AMERICA, INC.
  14. Connect the connector to the power steering pump switch.
    G08538645Courtesy of SUBARU OF AMERICA, INC.
  15. Connect the connector (A) to the engine coolant temperature sensor, connector (B) to the oil pressure switch, and the connector (C) to the crankshaft position sensor.
    G08538644Courtesy of SUBARU OF AMERICA, INC.
  16. Install the engine harness connector to engine harness bracket, then connect the bulkhead harness connector to the engine harness connector.
    G10264739Courtesy of SUBARU OF AMERICA, INC.
  17. Install the engine harness to clip (A).
    G11571459Courtesy of SUBARU OF AMERICA, INC.
  18. Connect the leak diagnosis connector to the leak diagnosis connector harness.
    G11571458Courtesy of SUBARU OF AMERICA, INC.
  19. Connect the leak diagnosis connector to the engine harness, and secure the leak diagnosis connector harness with the tape (A) as shown in the figure below.
    G11571457Courtesy of SUBARU OF AMERICA, INC.
  20. Install the engine coolant hose to the water tank pipe.
    G08538640Courtesy of SUBARU OF AMERICA, INC.
  21. Connect the air control hose (A) to the wastegate actuator, and install the turbocharger to the intake duct.

    Tightening torque: 

    3 N.m (0.3 kgf-m, 2.2 ft-lb)

    G06344555Courtesy of SUBARU OF AMERICA, INC.
  22. Connect the vacuum hose (A) and connector (B) to the PCV hose assembly B.
    G11571454Courtesy of SUBARU OF AMERICA, INC.
  23. Install the PCV hose to the clip.
    G11571453Courtesy of SUBARU OF AMERICA, INC.
  24. Connect the brake booster vacuum hose (A) and pressure regulator vacuum hose (B) to the intake manifold.
    G08538635Courtesy of SUBARU OF AMERICA, INC.
  25. Connect the engine coolant hoses to throttle body.
    G08538634Courtesy of SUBARU OF AMERICA, INC.
  26. Install the A/C pressure hoses to A/C compressor. Refer to HVAC SYSTEM (HEATER, VENTILATOR AND A/C)>HOSE AND PIPE>INSTALLATION .
  27. Install the coolant filler tank. Refer to COOLING(STI)>COOLANT FILLER TANK>INSTALLATION .
  28. Install the generator. Refer to STARTING/CHARGING SYSTEMS(STI)>GENERATOR>INSTALLATION .
  29. Install the air by-pass valve. Refer to INTAKE (INDUCTION) (STI)>AIR BY-PASS VALVE>INSTALLATION .
  30. Install the air intake boot.

    Tightening torque: 

    2.5 N.m (0.3 kgf-m, 1.8 ft-lb)

    G13257296Courtesy of SUBARU OF AMERICA, INC.
  31. Install the intercooler. Refer to INTAKE (INDUCTION) (STI)>INTERCOOLER>INSTALLATION .
  32. Install the air intake duct. Refer to INTAKE (INDUCTION) (STI)>AIR INTAKE DUCT>INSTALLATION .
  33. Connect the battery ground terminal.
  34. Lift up the vehicle.
  35. Install the under cover. Refer to EXTERIOR/INTERIOR TRIM>FRONT UNDER COVER>INSTALLATION .
  36. Lower the vehicle.
  37. Install the V-belt cover.

    Tightening torque: 

    7 N.m (0.7 kgf-m, 5.2 ft-lb)

    G06344549Courtesy of SUBARU OF AMERICA, INC.
  38. Fill engine coolant. Refer to COOLING(STI)>ENGINE COOLANT>REPLACEMENT>FILLING OF ENGINE COOLANT .
  39. Charge the A/C system with refrigerant. Refer to HVAC SYSTEM (HEATER, VENTILATOR AND A/C)>REFRIGERANT CHARGING PROCEDURE>PROCEDURE .
scientia non olet · About LEMON Manuals