2018 Subaru WRX BaseFACTORY OEM SERVICE PROCEDURE

Fuel Injector: Replacement

CAUTION:
  • Perform work without using gloves.
  • Always use the ST when installing the injector seal.

ST 18683AA000

INJECTOR SEAL INSTALLER

G12444128
  1. Using a pair of nippers, cut off the injector seal by pinching it.
    CAUTION: Be careful not to damage the fuel injector.
    G09479680
  2. Remove the O-ring and backup ring from the fuel injector.
    G09479681
  3. Attach the seal guide A to the fuel injector.
    NOTE: Two types of seal guides are provided. So, do not mix up the type to be used.
    G09479682
  4. Set the injector seal to the injector seal installer.
    G09479683
  5. Push in the injector seal installer slowly in the direction of the arrow, and attach the injector seal to the fuel injector.
    CAUTION:
    • Insert it so that the injector seal is installed straight.
    • Be careful that the injector seal does not go beyond the fuel injector groove.
    G09479684
  6. While rotating the injector seal adjuster to left and right by 90 degrees for each side, slowly insert it all the way.
    NOTE:
    • Apply a thin coat of gasoline to the injector seal and injector seal adjuster.
    • With the injector seal adjuster fully inserted, rotate it to left and right approx. ten times by 90 degrees for each side to normalize the injector seal.
    G09479685
  7. Attach the seal guide B to the fuel injector.
    NOTE: Two types of seal guides are provided. So, do not mix up the type to be used.
    G09479686
  8. Set the injector seal to the injector seal installer.
    G09479683
  9. Push in the injector seal installer slowly in the direction of the arrow, and attach the injector seal to the fuel injector.
    CAUTION:
    • Insert it so that the injector seal is installed straight.
    • Be careful that the injector seal does not go beyond the fuel injector groove.
    G09479688
  10. While rotating the injector seal adjuster to left and right by 90 degrees for each side, slowly insert it all the way.
    NOTE:
    • Apply a thin coat of gasoline to the injector seal and injector seal adjuster.
    • With the injector seal adjuster fully inserted, rotate it to left and right approx. ten times by 90 degrees for each side to normalize the injector seal.
    G09479685
  11. Attach two backup rings and O-ring to the fuel injector.
    NOTE: Use new backup rings and O-ring.
    G12444139
Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

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