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Home >> Kia >> 2010 >> Forte SX, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System Diagnosis (ULEV) (1 Of 2) >> DTC P0420: Catalyst System Efficiency below Threshold (Bank 1) >> General Information >> DTC Detecting Condition
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General Information: DTC Detecting Condition

DTC DETECTING CONDITION CHART

Item Detecting Condition Possible Cause
DTC Strategy
  • Check catalyst oxygen storage capacity by evaluating downstream O2 sensor fluctuations
  • Exhaust gas leaks
  • Faulty rear HO2S
  • Faulty three way catalyst converter
Enable Conditions
  • Coolant temperature >73°C (163°F)
  • 550°C (1022°F)< Modeled catalyst temp <850°C (1562°F)
  • Vehicle speed >3mph
  • 1300< Engine speed <3200
  • 0.3g/rev.< MAF < 0.8g/rev.
  • Ambient pressure > 70kPa (700hPa)
  • Canister load < 0.5
  • Lambda control active & Stable driving condition
  • Downstream O2 sensor operative readiness
  • No opening/closing of Canister Purge Valve
  • No relevant failure
  • 11V < Battery voltage < 16V
Threshold Value
  • Average malfunction index > 1
Diagnostic Time
  • 50 Lambda Controller Cycles
MIL On Condition
  • 2 Driving Cycles