Mazda 6 Service Manual: No.22 vibration concerns (engine)

No.21 engine noise

No.23 a/c does not work sufficiently

Other materials:

Mazda 6 Service Manual: Add-On Non-Genuine Parts and Accessories
Non-genuine parts and accessories for Mazda vehicles can be found in stores. These may fit your vehicle, but they are not approved by Mazda for use with Mazda vehicles. When you install non-genuine parts or accessories, they could affect your vehicle's performance or safety systems; the Mazda w ...

Mazda 6 Service Manual: Camshaft position (cmp) sensor inspection
Caution When foreign material such as an iron chip is on the CMP sensor, it can cause abnormal output from the sensor because of flux turbulence and adversely affect the engine control. Be sure there is no foreign material on the CMP sensor when replacing. Note Perform the follow ...