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Home >> Hyundai >> 2018 >> Kona Limited, FWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 380 (Engine Control System Diagnosis - 1.6L (4 Of 6)) >> DTC P0420-00: Catalyst System Efficiency Below Threshold (Bank 1) >> DTC Information >> DTC Detecting Condition

DTC Information: DTC Detecting Condition

WARNING: This page is about a different car, the 2023 Kia Seltos. However, it is still accessible from the selected car via links, so may be relevant.
Item Detecting Condition Possible Cause
Verification Of Repair 
DTC Strategy
  • Check catalyst Oxygen Storage Capacity (OSC)
  • Exhaust system
  • S2
  • Catalyst converter
  • Out of range ECT sensor
  • Exhaust manifold
  • High fuel pressure
  • Incorrect connection
  • Misfire
  • Injector
  • EGR system
Enable Conditions
  • Engine speed is between 1200 and 3000RPM
  • Engine load is between 18 and 90%
  • Catalyst temperature (model) is between 600 and 850°C (1112 and 1562°F)
  • Catalyst mass flow is between 40 and 140 kg/h
  • Fuel system status is closed loop
  • Change amount of catalyst temperature (model) is less than 40°C (104°F)
  • Change amount of catalyst mass flow is 45 kg/h
Threshold Value
  • Ratio of actual OSC to model OSC is less than 1.0
Diagnostic Time
  • 15s
MIL ON Condition
  • 2 driving cycles