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 < 600°C (1112°F) Coolant temperature > 70°C (158°F) Lambda control within limit 992 < Engine speed(rpm) < 2880 Air mass flow(mg/rev.) < 750 No misfire is detected Not Transient Condition as Below Engine Speed [ Current - Mean ] < 350rpm TPS [ Current - Mean ] < 4.2° TPS Lambda Correction [ Current - Mean ] < 4%
Threshold Value	Averaged malfunction index > 0.7
Diagnostic Time	120 lambda controller cycles
MIL On Condition	2 Driving Cycles