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: Fuel pump unit removal/installation
Warning
Fuel line spills and leakage are dangerous. Fuel can ignite and
cause serious injuries or death and damage. Fuel can also irritate skin and
eyes. To prevent this, do not damage the sealing surface of the fuel pump
unit when removing or installing.
Caution
Disconnecting/co ...
Mazda 6 Service Manual: No.3 passenger-side air bag cut-off indicator light does not illuminate
Diagnostic Procedure
When performing an asterisked (*) troubleshooting inspection, shake the
wiring harness and connectors while doing the inspection to discover whether
poor contact points are the cause of any intermittent malfunction. If there
is a problem, check to make sure connec ...