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: Electrical troubleshooting tools
Jumper wire
A jumper wire is used to create a temporary circuit. Connect the jumper
wire between the terminals of a circuit to bypass a switch.
Caution
Do not connect a jumper wire from the power source line to a body
ground. This may cause burning or other damage to wiring harnesse ...
Mazda 6 Service Manual: Traction Control System (TCS)
The Traction Control System (TCS) enhances traction and safety by controlling
engine torque and braking. When the TCS detects driving wheel slippage, it lowers
engine torque and operates the brakes to prevent loss of traction.
This means that on a slick surface, the engine adjusts automatically ...