My vehicle(Mazda 3)'s engine.

Hi,

My vehicle(Mazda 3)'s engine light came on and I plugged in the OBD adapter to check and I got the messages below using an application called OBDScope. I did reset the engine light by unplugging the negative terminal of the battery and after 400km it came back on again. The car still feels fine and drives well

Any help will be appreciated.

Diagnosis by OBDSCOPE
MIL: On.
Inspection status: Failed. MIL is on.
Fuel system status: Open loop due to engine load.
Secondary air status: N/A.
Time Since Engine Start: 0s
Distance with MIL: 11km
# Of Warm-ups Since DTCs Cleared: 10
Engine Coolant Temperature: 93°C
OBD Port Voltage: 12.20V
OBD tests: 6/6 completed:
Misfire: OK
Fuel system: OK
Components: OK
Catalyst: OK
Oxygen sensor: OK
Oxygen sensor heater: OK
Lambda Tests:
Short Term Fuel Trim B1: No variation, 0.0000%
O2 Sensor B1S1: Varies between 0.0200V - 0.0250V
O2 Sensor B1S2: No variation, 0.0300V
DTCs:
P0420(current): Catalyst System Efficiency Below Threshold (Bank 1)
P0420(pending): Catalyst System Efficiency Below Threshold (Bank 1).
Freeze Frame:
DTC: P0420
Calculated Load: 37%
Engine Coolant Temperature: 84°C
Short Term Fuel Trim B1: 9%
Long Term Fuel Trim B1: -5%
Engine RPM: 26721/min
Vehicle Speed: 86km/h
Timing advance: 48°
Intake Air Temperature: 32°C
Air Flow Rate: 11g/s
Absolute Throttle Position: 15%
Time Since Engine Start: 822s
Commanded EGR: 46%
Commanded Evaporative Purge: 77%
# Of Warm-ups Since DTCs Cleared: 9
Distance Since DTCs Cleared: 400km
Barometric Pressure: 85kPa(a)
Catalyst Temperature B1S1: 734°C
Control Module Voltage: 14V
Absolute Load Value: 27%
Commanded Equivalence Ratio: 1
Relative Throttle Position: 5%