Detection Condition
WARNING: This page is about a different car, the 2002 Mazda B4000, 2002 Mazda B3000, and 2002 Mazda B2300. However, it is still accessible from the selected car via links, so may be relevant.
DTC P1127 indicates that the inferred exhaust temperature to determine when HO2S heaters are cycled ON is less than a calibrated value.