Function Explanation (DTC Detection Outline): P2097:00

If a condition in which the feedback correction amount from the HO2S signal is small (fuel injection amount being decreased) continues for the specified time (25 s) , the PCM determines a feedback correction amount malfunction and stores a DTC.
A condition in which the fuel feedback correction amount (SHRTFT12) for the HO2S is the specified value (-2 %) or less and the sum (SHRTFT12+LONGFT12) of the fuel feedback correction amount and the fuel learning correction amount is the specified value (-2.5- -2.3 %) or less continues for a period of 25 s .

Fig 1: Fuel Feedback Correction Amount Waveform (P2097:00)
Courtesy of MAZDA MOTORS CORP.