GM Service Manual Online
For 1990-2009 cars only

Removal Procedure


    Object Number: 661778  Size: SH
  1. Remove the mass air flow (MAF) sensor (10). Refer to Mass Airflow Sensor/Intake Air Temperature Sensor Replacement .
  2. Remove the intake resonance switchover valve assembly (3). Refer to Intake Resonance Switchover Valve Replacement .
  3. Disconnect the switchover valves solenoid electrical connector.
  4. Disconnect the vacuum connections at the switchover valve solenoid and the vacuum reservoir (4).
  5. Remove and discard the cable tie that retains the vacuum lines.
  6. Remove the intake air resonator (7).

Installation Procedure


    Object Number: 661778  Size: SH
  1. Install the intake air resonator.
  2. Insert the intake air resonator guide pin into the rubber mount (8).
  3. Connect the vacuum connections at the switchover valve and the vacuum tank.
  4. Install a new cable tie to retain the vacuum lines.
  5. Connect the electrical connector to the switchover valve.
  6. Install the intake resonance switchover valve assembly . Refer to Intake Resonance Switchover Valve Replacement .
  7. Install the mass air flow (MAF) sensor. Refer to Mass Airflow Sensor/Intake Air Temperature Sensor Replacement .