Secondary Air Injection Pump

This procedure covers the removal and replacement of the secondary air injection pump on the 2018-2024 Honda Accord 1.5L turbocharged engine, which supplies fresh air to the exhaust system during cold starts to reduce emissions.

Warnings

Tools required

Parts

• Secondary air injection pump assembly × 1 — Use OEM specification
• Air pump mounting gasket × 1 — Use OEM specification
• Secondary air pipe gasket × 1 — Use OEM specification

Preparation

1. Ensure engine is completely cold to the touch
2. Disconnect negative battery terminal and wait 3 minutes for electrical systems to discharge
3. Raise hood and secure with prop rod
4. Remove engine cover by pulling upward on all four corners to release retaining clips
5. Locate secondary air injection pump on driver's side of engine compartment
6. Take photos of electrical connector orientations and hose routings for reassembly reference

Procedure

1. 1

   Remove heat shield
   Locate the heat shield covering the secondary air injection pump and exhaust components. Remove the heat shield mounting bolts using a 10mm socket. Carefully remove the heat shield and set aside.
   Torque spec

   Heat Shield Bolts10 Nm (7 lb-ft)
2. 2

   Disconnect electrical connector
   Locate the electrical connector on the secondary air injection pump. Press the locking tab and disconnect the connector from the pump. Move the wiring harness aside to provide clearance.
   ℹ️Some connectors have a secondary locking tab that must be lifted before the main connector can be released.
3. 3

   Remove air intake hose
   Loosen the hose clamp securing the fresh air intake hose to the secondary air pump using a flathead screwdriver or 7mm socket. Disconnect the intake hose from the pump and move it aside.
   ℹ️The intake hose draws fresh air from the engine bay. Inspect the hose for cracks or damage during removal.
4. 4

   Disconnect outlet pipe
   Locate the secondary air outlet pipe connection at the pump. Remove the flange bolts securing the outlet pipe to the pump using a 12mm socket. Separate the pipe from the pump and note the gasket location.
   ⚠The outlet pipe connects to the hot exhaust system. Verify the engine is cool before handling this component.
   Torque spec

   Exhaust Flange Bolts45 Nm (33 lb-ft)
5. 5

   Remove pump mounting bolts
   Support the secondary air pump with one hand. Remove the pump mounting bolts using a 12mm socket and extension. There are typically two or three mounting bolts securing the pump to its bracket. Keep track of any spacers or washers.
   Torque spec

   Mounting Bolts26 Nm (19 lb-ft)
6. 6

   Remove secondary air pump
   Carefully maneuver the secondary air pump out of the engine bay. You may need to rotate or angle the pump to clear surrounding components. Inspect the pump mounting area for debris or damage.
   ℹ️The pump is moderately heavy and awkward to remove from the tight engine bay. Work carefully to avoid dropping it or damaging surrounding components.
7. 7

   Inspect and clean mounting surfaces
   Remove old gasket material from the pump mounting bracket and outlet pipe flange using a plastic scraper. Do not use metal tools that could damage sealing surfaces. Clean all mounting surfaces with brake cleaner and allow to dry completely.
   ⚠Ensure no debris or old gasket material enters the outlet pipe opening, as this could contaminate the exhaust system.
8. 8

   Install new pump
   Position the new or replacement secondary air pump in the mounting bracket. Install the mounting bolts finger-tight, ensuring any spacers or washers are properly positioned. Torque the mounting bolts to specification in a cross pattern.
   Torque spec

   Mounting Bolts26 Nm (19 lb-ft)
9. 9

   Connect outlet pipe
   Install a new gasket on the outlet pipe flange. Position the outlet pipe to the pump and install the flange bolts finger-tight. Torque the flange bolts to specification in a cross pattern to ensure even gasket compression.
   Torque spec

   Exhaust Flange Bolts45 Nm (33 lb-ft)
10. 10

    Reconnect intake hose and electrical
    Connect the fresh air intake hose to the pump inlet and secure with the hose clamp. Reconnect the electrical connector to the pump, ensuring it clicks fully into place and the locking tab engages.
    ℹ️Verify the electrical connector is fully seated. A partially connected plug will cause system malfunction and diagnostic codes.
11. 11

    Reinstall heat shield
    Position the heat shield over the secondary air pump and exhaust components. Install and torque the heat shield bolts to specification.
    Torque spec

    Heat Shield Bolts10 Nm (7 lb-ft)

Reassembly

1. Reinstall engine cover by aligning clips and pressing down firmly at all four corners until seated
2. Reconnect negative battery terminal and torque to 10 Nm (7 lb-ft)
3. Verify all tools and parts have been removed from engine bay

Verification

• Start the engine and allow it to idle. Listen for unusual noises from the secondary air pump area
• Allow the engine to fully warm up to operating temperature, then turn off and let cool completely
• Perform a cold start test: start the cold engine and listen for the secondary air pump to activate (typically runs for 60-120 seconds during cold start)
• Check for exhaust leaks around the outlet pipe connection while the pump is operating
• Use an OBD-II scanner to verify no diagnostic trouble codes are present related to the secondary air injection system (P0410, P0411, P0412, P0418)
• Verify the check engine light is not illuminated after several cold start cycles
• Inspect all connections for signs of leaks or looseness after test drive

Related trouble codes on this vehicle

Codes that commonly send this job to the bay — tap one for symptoms, causes, and diagnostic steps.

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