Air Injection Check Valve

This procedure covers the removal and replacement of the air injection check valve on the 2017 Maserati Levante 3.0L V6 Twin Turbo, which prevents exhaust gases from entering the secondary air injection system.

Warnings

Tools required

Parts

• Air injection check valve × 1 — Use OEM specification
• Check valve gasket or seal × 1 — Usually included with valve

Preparation

1. Ensure engine is completely cool to the touch (minimum 1 hour after last operation)
2. Park vehicle on level ground and engage parking brake
3. Disconnect negative battery terminal to prevent accidental electrical issues
4. Remove engine cover by pulling upward on cover retention clips
5. Spray penetrating oil on all exhaust fasteners that will be removed and allow 15 minutes soak time
6. Locate the air injection check valve assembly on the driver's side of the engine compartment

Procedure

1. 1

   Disconnect electrical connections
   Locate and disconnect any electrical connectors related to the secondary air injection system. Press the release tab and pull connector straight off. On this engine, the air pump connector is typically located near the check valve assembly.
2. 2

   Remove heat shield
   Remove the heat shield bolts securing the exhaust heat shield near the check valve. There are typically 2-3 bolts. Carefully remove the heat shield to access the check valve mounting area. Set heat shield aside in a safe location.
3. 3

   Disconnect air supply hose
   Loosen the hose clamp securing the air supply hose to the check valve inlet using a flat blade screwdriver or 10mm socket. Disconnect the rubber hose from the check valve. Inspect hose for cracks or deterioration and replace if necessary.
4. 4

   Disconnect check valve outlet connection
   The check valve outlet connects to the exhaust system via a flanged connection. Remove the mounting bolts or flange bolts securing the check valve to the exhaust pipe. If bolts are severely corroded, apply additional penetrating oil and use a wire brush to clean threads.
   ⚠Support the check valve with one hand while removing the final bolt to prevent it from falling and damaging components below.
5. 5

   Remove check valve mounting bracket
   If the check valve is secured with a separate mounting bracket, remove the mounting bolts holding the bracket to the engine or chassis. Use a 13mm socket with extension to access bolts. Keep all hardware organized for reinstallation.
6. 6

   Remove check valve assembly
   Carefully remove the check valve assembly from the vehicle. Note the orientation and positioning of the valve for proper installation of the replacement. Remove and discard the old gasket or seal from the mating surface.
7. 7

   Clean mating surfaces
   Using a wire brush or gasket scraper, thoroughly clean all mating surfaces on the exhaust flange connection. Remove all carbon deposits, old gasket material, and corrosion. Ensure surfaces are clean and flat for proper sealing.
   ⚠Do not gouge or damage mating surfaces as this will cause exhaust leaks. Use plastic scrapers on aluminum surfaces.
8. 8

   Prepare new check valve
   Unpack the new check valve and verify it matches the original. Install the new gasket or seal onto the valve. Ensure the arrow or flow direction marking on the valve body points toward the exhaust system (downstream direction).
9. 9

   Install check valve assembly
   Position the new check valve in the correct orientation with the flow arrow pointing toward the exhaust. Align the mounting bracket (if applicable) and start all mounting bolts by hand to ensure proper thread engagement before tightening.
10. 10

    Secure mounting bracket
    Tighten the mounting bracket bolts to specification using a torque wrench. Ensure the valve is properly supported and aligned before final tightening.
11. 11

    Connect valve to exhaust system
    Apply a thin layer of high-temperature anti-seize compound to the flange bolt threads. Install the flange bolts connecting the check valve outlet to the exhaust pipe. Tighten bolts in a cross-pattern to specification to ensure even gasket compression.
12. 12

    Reconnect air supply hose
    Connect the air supply hose to the check valve inlet. Ensure the hose is fully seated onto the barbed fitting. Position the hose clamp over the connection point and tighten securely. Verify there is no interference with nearby components.
13. 13

    Reinstall heat shield
    Position the heat shield back into place, ensuring it does not contact any moving components or wiring. Install and tighten heat shield bolts to specification.
14. 14

    Reconnect electrical connections
    Reconnect all electrical connectors to the secondary air injection system components. Ensure connectors click into place and locking tabs are fully engaged.

Reassembly

1. Reinstall engine cover by aligning clips and pressing down firmly until all clips engage
2. Reconnect negative battery terminal and tighten securely
3. Clear any diagnostic trouble codes using a scan tool if check engine light was illuminated

Verification

• Start the engine and allow it to reach operating temperature while monitoring for unusual noises from the air injection system
• Listen carefully near the check valve area for any hissing or exhaust leaks. A properly installed valve should be silent
• Perform a cold start test if possible, as the secondary air system typically operates during cold start for emissions control
• Use a scan tool to verify the secondary air injection system is functioning properly with no fault codes present
• Check for proper airflow direction by feeling for air movement at the air pump outlet during system operation (engine cold start)
• Verify no exhaust odors are present in the engine bay, which would indicate a leak at the check valve connection

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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