Erratic Or Hunting Shifting
WARNING: This page does not describe the selected car, but rather 13 other vehicles, including the 2003 Mazda B4000, 2003 Mazda B3000, 2003 Mazda B2300, 2002 Mazda B4000, and 2002 Mazda B3000. However, it is still accessible from the selected car via links, so may be relevant.
Check the following: improper fluid level and condition, filter assembly (plugged), filter seal damaged or missing, valve body (SS1, SS2, SS3, SS4 and EPC solenoids), incorrectly tightened valve body bolts (cross-leaks), or Torque Converter Clutch (TCC).