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: Fuel pump unit inspection
Caution It is normal to hear the fuel pump operating when the ignition switch is turned to the ON position. Note To improve startability, the fuel pump control operates the fuel pump unit when the ignition switch is turned to the ON position. Due to this, fuel pressure is rapidly ...

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 ...