Mazda 6 Service Manual: No.12 lack/loss of power-acceleration/cruise

No.11 engine stalls/quits, engine runs rough, misses, buck/jerk, hesitation/stumble, surges

No.13 knocking/pinging-acceleration/cruise

Other materials:

Mazda 6 Service Manual: Inspecting Electrolyte Level
A low level of electrolyte fluid will cause the battery to discharge quickly. Inspect the electrolyte level at least once a week. If it is low, remove the caps and add enough distilled water to bring the level between the upper and lower level (illustration). Do not overfill. Examine the sp ...

Mazda 6 Service Manual: Expansion valve removal/installation
1. Disconnect the negative battery cable. 2. Discharge the refrigerant from the system. (See RECOVERY.) (See CHARGING.) Caution If moisture or foreign material enters the refrigeration cycle, cooling ability will be lowered and abnormal noise will occur. Always immediately plug open fitt ...