Mazda 6 Service Manual: No.23 a/c does not work sufficiently

No.22 vibration concerns (engine)

No.24 a/c is always on or a/c compressor runs continuously

Other materials:

Mazda 6 Service Manual: Mass air flow (maf) sensor inspection
Voltage Inspection Note Perform the following inspection only when directed. 1. Visually inspect for the following on the MAF sensor. Damage Cracks Terminal bends Terminal rust - If any of the above are found, replace the MAF sensor. - If the MAF PID value is out of specifi ...

Mazda 6 Service Manual: Manual Transaxle Shift Pattern
  The shift pattern of the transaxle is conventional, as shown. Depress the clutch pedal all the way down while shifting; then release it slowly. Your vehicle is equipped with a device to prevent shifting to R (reverse) by mistake. Push the shift lever downward and shift to R.   ...