This procedure covers the removal and replacement of a single fuel injector on the 2014-2019 Toyota Corolla 1.8L I4 engine, including fuel system depressurization and fuel rail removal.

Warnings

Tools required

Parts

• Fuel injector × 1 — Use OEM specification or Denso equivalent
• Fuel injector O-ring set × 1 — Upper and lower O-rings
• Fuel line O-rings × 2 — Use OEM specification

Preparation

1. Ensure engine is completely cool
2. Disconnect negative battery terminal and wait 90 seconds for airbag system to discharge
3. Remove engine cover by pulling upward on cover to release clips
4. Place catch pan and shop towels under fuel system work area

Procedure

1. 1

   Relieve fuel system pressure
   Remove fuel pump relay (located in engine compartment fuse box - consult fuse diagram on box lid). Attempt to start engine and let it run until it stalls. Attempt to start 2-3 more times to ensure all pressure is relieved. Turn ignition off and reinstall fuel pump relay.
2. 2

   Disconnect fuel feed line
   Locate the fuel feed line on the fuel rail. Using the appropriate fuel line disconnect tool, press the release tabs and carefully pull the fuel line straight off the fuel rail. Some residual fuel will drain - catch with shop towels. Cap the line to prevent contamination.
   ⚠Even after pressure relief, residual fuel will spill. Have towels ready and work carefully.
3. 3

   Disconnect injector electrical connectors
   Press the lock tab on each of the four fuel injector electrical connectors and pull straight up to disconnect. Move harness aside for clearance. Mark or photograph injector positions if planning to replace multiple injectors later.
4. 4

   Remove fuel rail mounting bolts
   Using a 12mm socket, remove the two fuel rail mounting bolts. Keep bolts organized for reinstallation. Note the location of any ground straps or brackets that may be attached.
   Torque spec

   Fuel Rail Bolts12 Nm (9 lb-ft)
5. 5

   Remove fuel rail assembly
   Carefully pull the fuel rail straight up and away from the cylinder head. The injectors will come out with the rail. Work the rail back and forth gently if resistance is encountered - do not pry. Once free, place the rail on a clean work surface with injectors facing upward.
   ⚠Do not bend or damage fuel rail. Apply even upward pressure to avoid breaking injector tips.
6. 6

   Remove retaining clip from target injector
   Locate the metal retaining clip securing the injector to the fuel rail. Using a small flathead screwdriver or needle nose pliers, pry or pull the clip to release it from the fuel rail. Set clip aside if reusing.
7. 7

   Extract fuel injector
   Grasp the injector body firmly and pull straight out from the fuel rail with a twisting motion. Remove and discard both O-rings (upper at fuel rail and lower at intake manifold) from the old injector.
8. 8

   Prepare new fuel injector
   Lubricate new O-rings with clean gasoline or light oil. Install the upper O-ring onto the new injector at the fuel rail interface position and the lower O-ring at the intake manifold seal position. Ensure O-rings are properly seated in their grooves.
   ℹ️Use only new O-rings. Old O-rings will leak even if they appear undamaged.
9. 9

   Install new injector into fuel rail
   Insert the new fuel injector into the fuel rail opening, aligning the electrical connector orientation to match the other injectors. Push firmly until fully seated. Reinstall the retaining clip, ensuring it fully engages to lock the injector in place.
10. 10

    Inspect intake manifold injector bores
    Before reinstalling fuel rail, inspect the injector bores in the intake manifold. Remove any old O-ring material or debris using a clean shop towel. Ensure bores are clean and dry.
11. 11

    Reinstall fuel rail assembly
    Carefully align all four injectors with their respective bores in the intake manifold. Press the fuel rail downward evenly, ensuring all injectors seat fully into the manifold. Install the two fuel rail mounting bolts and torque to specification using a torque wrench.
    ⚠Ensure all injectors enter bores squarely to prevent damage to O-rings or injector tips.
    Torque spec

    Fuel Rail Bolts12 Nm (9 lb-ft)
12. 12

    Reconnect injector electrical connectors
    Push each injector electrical connector onto its corresponding injector until the lock tab clicks into place. Verify each connection is secure by gently pulling on the connector.
13. 13

    Reconnect fuel feed line
    Install new O-rings on the fuel line fitting if provided. Push the fuel feed line firmly onto the fuel rail connection until it clicks into place. Tug gently to verify it is locked.
    ℹ️Always replace fuel line O-rings when disconnecting fuel lines to prevent leaks.
    Torque spec

    Fuel Line Fittings25 Nm (18 lb-ft)
14. 14

    Reinstall engine cover
    Align the engine cover with its mounting points and press down firmly until all clips engage. Reconnect the negative battery terminal.

Reassembly

1. Ensure all electrical connectors are fully seated and locked
2. Verify fuel line connection is secure and properly locked
3. Double-check that fuel rail mounting bolts are torqued to specification

Verification

• Turn ignition to ON position (do not start) for 2 seconds, then OFF. Repeat 3-4 times to prime fuel system and build pressure
• Inspect all fuel connections for leaks while system is pressurized
• Start engine and verify it runs smoothly without misfires or rough idle
• Check for fuel odor or visible leaks around fuel rail and injectors while engine is running
• Use a scan tool to verify no fuel injector-related fault codes are present
• Allow engine to reach operating temperature and recheck for leaks

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