Mazda 6 Service Manual: No.13 knocking/pinging-acceleration/cruise

No.12 lack/loss of power-acceleration/cruise

No.14 poor fuel economy

Other materials:

Mazda 6 Service Manual: Foreword
When the customer reports a vehicle malfunction, check the malfunction indicator lamp (MIL) indication and diagnostic trouble code (DTC), then diagnose the malfunction according to following flowchart. - If a DTC exists, diagnose the applicable DTC inspection. (See DTC TABLE.) - ...

Mazda 6 Service Manual: Variable air duct (vad) shutter valve inspection (l3)
1. Remove the air cleaner case. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION.) 2. Disconnect the vacuum hose from the VAD shutter valve actuator. 3. Connect a vacuum pump to the VAD shutter valve actuator. 4. Apply vacuum and verify that the rod moves. If the rod dose not move, replace the a ...