Mazda 6 Service Manual: No.6 cranks normally but will not start

No.5 engine stalls-after start/at idle

No.7 slow return to idle

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: Cruise Control Function
While this function is operating, the headway control operation is canceled and only the cruise control function operates. The vehicle speed can be set more than about 25 km/h (16 mph). Use the cruise control function on expressways and other highways which do not require a lot of repeated acc ...