Mazda 6 Service Manual: No.15 engine flares up or slips when accelerating vehicle

No.14 engine flares up or slips when upshifting or downshifting

No.16 judder upon torque converter clutch (tcc) operation

Other materials:

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.   ...

Mazda 6 Service Manual: Fuel tank removal/installation
Warning Repairing a fuel tank that has not been properly steam cleaned can be dangerous. Explosion or ire may cause death or serious injury. Always properly steam clean a fuel tank before repairing it. Fuel line spills and leakage are dangerous. Fuel can ignite and cause serious injur ...