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Home >> Kia >> 2019 >> Forte EX >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System Diagnosis (3 Of 6) >> DTC P0420-00: Catalyst System Efficiency Below Threshold (Bank 1) >> DTC Information >> DTC Detecting Condition

DTC Information: DTC Detecting Condition

Item Detecting Condition Possible Cause
DTC Strategy
  • Check Catalyst oxygen storage capacity
  • Exhaust system
  • Faulty downstream O2 sensor
  • Catalyst converter
  • Out of range ECT sensor
  • Exhaust manifold
  • High fuel pressure
  • Incorrect connection
  • Misfire
  • Injector
  • EGR system
Enable Conditions
  • Coolant temperature is higher than 73°C (163°F)
  • Modeled catalyst temperature is higher than 1022°F and lower than 1526°F
  • Vehicle speed is higher than 3 mph
  • Engine speed is higher than 1300RPM and lower than 3200RPM
  • MAF is higher than 0.3g/revolution and lower than 0.9g/revolution
  • Ambient pressure is higher than 70 kPa (700 hPa)
  • Canister load is lower than 0.5
  • Lambda control active & Stable driving condition
  • Downstream O2 sensor operative readiness
  • No opening/closing of Canister Purge Valve
  • No relevant failure
  • Battery voltage is higher than 11V and lower than 16V
Threshold Value
  • Average malfunction index is higher than 1
Diagnostic Time
  • 50 Lambda controller cycles
MIL ON Condition
  • 2 driving cycles