DTC P0420 Catalyst System Efficiency Below Threshold (Bank 1); DTC P0430 Catalyst System Efficiency Below Threshold (Bank 2): DTC Detecting Condition

DTC DETECTING CONDITION

Item	Detecting Condition	Possible Cause
DTC Strategy	Comparison of the signal ratio of upstream and downstream O2 sensor in a load and speed range	Exhaust gas leaks Rear HO2S malfunction Three way catalyst converter malfunction
Enable Conditions	400(752°F) < Catalyst model temperature < 900°C (1652°F) Coolant temperature > 70°C (158°F) Lambda control within limit 1200rpm < Engine speed < 3000rpm 300 < Air mass flow(mg/rev.) < 840 No misfire is detected Not transient condition
Threshold Value	Averaged malfunction index > 3
Diagnostic Time	80 lambda controller cycles
MIL On Condition	2 Driving Cycles