Mazda 6 Service Manual: No.20 fuel odor (in engine compartment)

No.19 exhaust smoke

No.21 engine noise

Other materials:

Mazda 6 Service Manual: Engine control system operation inspection
Main Relay Operation Inspection Verify that the main relay clicks when the ignition switch is turned to ON position and off. If there is no operation sound, inspect the following. - Main relay (See RELAY INSPECTION.) - Harness and connector between ignition switch and main relay termi ...

Mazda 6 Service Manual: Scheduled Maintenance (U.S.A., Canada, and Puerto Rico)
Follow Schedule 1 if the vehicle is operated mainly where none of the following conditions (severe driving conditions) apply. Repeated short-distance driving Driving in dusty conditions Driving with extended use of brakes Driving in areas where salt or other corrosive materials are used ...