Mazda 6 Service Manual: No.19 exhaust smoke

No.18 cooling system concerns-runs cold

No.20 fuel odor (in engine compartment)

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: Reporting Safety Defects (U.S.A.)
If you believe that your vehicle has a defect which could cause a crash or could cause injury or death, you should immediately inform the National Highway Traffic Safety Administration (NHTSA) in addition to notifying Mazda Motor Corporation (Your Mazda Importer/Distributor). If NHTSA receive ...