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: General procedures
PRECAUTION (CLUTCH)
Clutch Pipe Removal/Installation
Note
A common reservoir is used for the clutch and brake system fluid.
1. If clutch pipes have been disconnected any time during the procedure, add
clutch fluid (brake fluid), bleed the air, and inspect for leakage after the
procedure ...
Mazda 6 Service Manual: Obd drive mode
Performing the Drive Mode inspects the OBD system for proper operation.
The Drive Mode must be performed to ensure that no additional DTCs are
present.
During Drive Mode, the following systems are inspected:
- Oxygen sensor (HO2S)
- Oxygen sensor heater
- Catalytic converter (TW ...