Throttle Body

This procedure covers removal and replacement of the throttle body on the 2016-2021 Honda Civic 1.5L turbocharged engine, including disconnection of electrical connections and air intake components.

Warnings

Tools required

Parts

• Throttle body gasket × 1 — Use OEM specification
• Throttle body assembly (if replacing) × 1 — Honda 16400-5AA-A02 or equivalent

Preparation

1. Park vehicle on level surface and engage parking brake
2. Allow engine to cool for at least 30 minutes
3. Disconnect negative battery terminal and wait 3 minutes for system discharge
4. Remove engine cover by pulling upward on clip attachments

Procedure

1. 1

   Remove air intake assembly
   Loosen the air intake hose clamp at the throttle body using a flathead screwdriver. Loosen the clamp at the air filter box end. Disconnect the MAF sensor electrical connector by pressing the release tab. Remove the entire air intake tube by pulling away from the throttle body.
   Torque spec

   Air Intake Hose Clamps3 Nm (2 lb-ft)
2. 2

   Disconnect throttle body electrical connector
   Locate the throttle position sensor electrical connector on the right side of the throttle body. Press down on the locking tab and pull the connector straight out from the throttle body. Do not pull on the wires.
   ⚠The connector locking tab is fragile - apply pressure only to the tab, not the connector body
3. 3

   Inspect for coolant hoses (if equipped)
   Check if your specific model has coolant bypass hoses connected to the throttle body for cold weather operation. If present, use pliers to squeeze and slide the hose clamps back, then carefully twist and pull the hoses off the throttle body nipples. Have shop towels ready to catch minor coolant drips. If no coolant hoses are present, proceed to next step.
   ℹ️Not all 1.5T Civic models have heated throttle bodies - most use air-cooled design only
4. 4

   Remove throttle body mounting bolts
   Using an 8mm socket, remove the four throttle body mounting bolts in a crisscross pattern. Keep track of bolt locations as they may be different lengths. Support the throttle body with one hand as you remove the final bolt.
   Torque spec

   Throttle Body Bolts10 Nm (7 lb-ft)
5. 5

   Remove throttle body from intake manifold
   Carefully pull the throttle body straight away from the intake manifold. If coolant hoses were attached, maneuver the throttle body to clear them. The gasket may stick to either the throttle body or intake manifold surface.
   ⚠Do not drop the throttle body - the internal butterfly valve mechanism is delicate
6. 6

   Clean mounting surfaces
   Remove and discard the old gasket completely. Use shop towels to clean both the intake manifold mounting surface and the back of the throttle body (or new unit). Ensure no gasket material falls into the intake manifold. Inspect the intake manifold mounting surface for damage or warping.
   ⚠Cover the intake manifold opening with a clean shop towel to prevent debris from entering while cleaning
7. 7

   Install new gasket and position throttle body
   Place the new throttle body gasket onto the intake manifold with the locating pins properly seated. Position the throttle body (new or cleaned original) onto the gasket, ensuring the electrical connector is accessible and properly oriented. Align all four bolt holes.
   ℹ️The gasket has a specific orientation - ensure it matches the port shape exactly
8. 8

   Install and torque throttle body bolts
   Start all four throttle body mounting bolts by hand to ensure proper thread engagement. Using a torque wrench and 8mm socket, tighten the bolts in a crisscross pattern to the specified torque of 14.0 Nm (10 lb-ft). Verify all bolts are properly seated.
   Torque spec

   Throttle Body Bolts10 Nm (7 lb-ft)
9. 9

   Reconnect coolant hoses (if equipped)
   If your model has coolant hoses, slide them back onto the throttle body nipples ensuring they are fully seated. Position the hose clamps over the hose connection point and tighten to 4.0 Nm (3.0 lb-ft). Check that hoses are secure.
10. 10

    Reconnect electrical connector
    Push the throttle position sensor electrical connector firmly onto the throttle body until you hear and feel it click into place. Gently tug on the connector to verify it is locked.
    ℹ️The connector must click fully into place or a check engine light will result
11. 11

    Reinstall air intake assembly
    Position the air intake tube onto the throttle body inlet, ensuring proper seating. Connect the MAF sensor electrical connector. Tighten the hose clamp at the throttle body end to 4.0 Nm (3.0 lb-ft). Tighten the air box end clamp to the same specification.
    Torque spec

    Air Intake Hose Clamps3 Nm (2 lb-ft)

Reassembly

1. Reinstall engine cover by aligning clips and pressing down firmly until all clips engage
2. Reconnect negative battery terminal
3. Do not force any components during reassembly - all parts should fit naturally with proper alignment

Verification

• Turn ignition to ON position (do not start) and verify no warning lights appear on dash
• Start the engine and allow it to idle - verify smooth operation with no air leaks (hissing sounds)
• Check for coolant leaks around throttle body hose connections if equipped with heated throttle body
• Rev engine gently to 2000-3000 RPM and verify smooth throttle response with no hesitation
• Take vehicle for short test drive and verify proper throttle response and no check engine light
• If check engine light appears, use OBD2 scanner to verify throttle position sensor is reading correctly - may need throttle relearn procedure

Related trouble codes on this vehicle

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