P0420

System/Component
Catalyst System cylinder 1-3
Oxygen Sensor (upstream) cylinder 1-3
Oxygen Sensor (downstream) cylinder 1-3

Fault Code
P0420

Fault Type
Plausibility Yes
Signal No
Minimum Threshold No
Maximum Threshold No

Monitoring Method
time ration (rich and lean) of O2-sensor signals down and upstream catalyst. Malfunction criteria: 2 x standard + 4K.

Signal Type
ECM internal signal/value computation or compensation
pulsating signal
pulsating signal

Operating Range
Catalyst temperature (model) > 353°C
For both oxygen sensors, Oxygen Sensor Monitoring

Time Length and Frequency for Monitoring/Diagnosis
230 sec./ once per trip

Criteria for storing fault code
fault during 2 trips

Criteria for illuminating the MIL
Fault during 2 trips and end of 2nd trip

Criteria used for determining out of range values and input component rationality check
UBATT No
Ground No
Disconnect No

Electronic Control Module (ECM) If time ratios, rich to lean and lean to rich, during 235 lambda controller cycles is > 60 a fault will be detected.