1. Verify that the joint shaft is not twisted or cracked.
2. Turn the joint shaft by hand and verify that the bearing rotates smoothly and freely.

Drive shaft
Joint shaft removal/installationMazda 6 Service Manual: Throttle position (tp) sensor inspection
Note
Perform the following inspection only when directed.
Resistance Inspection
1. Perform the following test only when directed.
If as specified but TP PID value is out of specification, inspect
resistance of TP sensor.
If not as specified, inspect the following:
- Accelerato ...
Mazda 6 Service Manual: Variable tumble control system (vtcs) shutter valve actuator inspection
1. Remove the air hose. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION.)
2. Disconnect the vacuum hose from the VTCS shutter valve actuator.
3. Connect a vacuum pump to the VTCS shutter valve actuator.
4. Apply vacuum and verify that the rod moves.
If the rod dose not move, replace the intake ...