1. Disconnect the negative battery cable.
2. Remove the intake maniforld.(see INTAKE-AIR SYSTEM REMOVAL/INSTALLATION.)
3. Remove the PCV valve.
4. Blow through the valve and verify that air flows as specified.

Specification

Egr valve inspection
Three-way catalytic converter (twc) inspectionMazda 6 Service Manual: Driver Air Bag
The driver's air bag is mounted in the steering wheel.
When air bag crash sensors detect a frontal impact of greater than moderate force,
the driver's air bag inflates quickly helping to reduce injury mainly to the driver's
head or chest caused by directly hitting the steering wheel. For more d ...
Mazda 6 Service Manual: Engine coolant
ENGINE COOLANT LEVEL INSPECTION
Verify that the coolant level in the coolant reservoir is between the F and L
marks.
If the engine coolant level is below L, remove the radiator cap and add
coolant. (See COOLING SYSTEM SERVICE WARNINGS.)
ENGINE COOLANT REPLACEMENT
Warning
Drain the ...