Mazda 6 Service Manual: No.20 noise occurs at idle when vehicle is stopped in all positions/ranges

No.19 excessive shift shock on torque converter clutch (tcc)

No.21 noise occurs at idle when vehicle is stopped in d, s, l ranges, or in r position

Other materials:

Mazda 6 Service Manual: Floor Mat
We recommend the use of Genuine Mazda floor mats. WARNING Make sure the floor mats are hooked on the retention pins to prevent them from bunching up under the foot pedals: Using a floor mat that is not secured is dangerous as it will interfere with the accelerator and brake pedal operation, ...

Mazda 6 Service Manual: Intake air temperature (iat) sensor inspection
Resistance Inspection Note Perform the following inspection only when directed. 1. Disconnect MAF/IAT sensor. 2. Measure the resistance between the MAF/IAT sensor terminals D and E using an ohmmeter. If not as specified, replace the MAF/IAT sensor. If the MAF/IAT sensor is okay, but ...