DTC P0456: EVAP System Leak Detected (Very Small Leak)

Fig 1: DTC P0456 Detection Condition & Possible Causes Chart

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Diagnostic Procedure 

Fig 2: DTC P0456 Diagnostic Procedure Chart (Step 1-3)

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Fig 3: DTC P0456 Diagnostic Procedure Chart (Step 4-11)

Courtesy of MAZDA MOTORS CORP.