Intake Manifold Check Valve

Disconnect air pump-to-air control valve air hose at the air pump. Install tachometer and start engine. Disconnect switching solenoid valve connector. Accelerate engine to 1500 RPM. Check for exhaust leakage at air control valve inlet fitting. See Fig 1 . Replace check valve if leakage exists.

Fig 1: Checking Intake Manifold Check Valve

Courtesy of MAZDA MOTORS CORP.