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Home >> Hyundai >> 2005 >> Elantra GLS, 4D Hatchback, Automatic >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Fuel System >> DTC Troubleshooting Procedures >> DTC P0420: Catalyst System Efficiency Below Threshold (Bank 1) >> DTC Detecting Condition
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DTC P0420: Catalyst System Efficiency Below Threshold (Bank 1): DTC Detecting Condition

DTC DETECTING CONDITION

Item Detecting Condition Possible Cause
DTC Strategy
  • Check catalyst oxygen storage capacity by evaluation downstream O2 sensor fluctuations
  • Exhaust gas leaks
  • Faulty rear HO2S
  • Faulty three way catalyst converter
Enable Conditions
  • Coolant temperature < 74°C (165°F)
  • Vehicle speed > 5km/h(3MPH)
  • Ambient pressure > 700 hPa
  • 1200rpm < Engine speed < 3500rpm
  • 200 < Mass air flow(mg/rev.) < 780
  • Stable driving condition
  • Canister load < 0.5
  • Catalyst temp. model 300°C (572°F) -730°C (1346°F)
  • Lambda control / Forced stimulation active
  • (VLS_DOWN > 0.68V or < 0.21V) or Catalyst model temp > 500°C
  • Engine operating state Part load
  • No relevant failure
  • 11V < Battery voltage < 16V
Threshold Value
  • Integral of VLS_DOWN - VLS_DOWN filtered > thd.
Diagnostic Time
  • 20 forced stimulation cycles