P0420

P0420 00

Three Way Catalytic Converter. Malfunction.







Fault symptom
Check Engine (OBD II, EOBD).

On-board diagnosis

Type of diagnosis:
Once per driving cycle. Stopped when fault criteria are fulfilled or OK reported.

Enable criteria:
Motor running for more than 230 s.
Accelerator pedal released.
Exhaust temperature between 400 and 750 degree C.
Vehicle speed less than 25 km/h.
No DTC detected for oxygen sensors 1 and 2.
No DTC detected for the mass air flow sensor.
No DTCs detected for exhaust temperature sensor (applies if sensor is fitted and earlier software, MY 03).
Idling speed increased, idling speed stabilized through ignition reduction.
Closed loop delayed in rich mode until O2S2 shows rich.
Closed loop delayed in lean mode and time is measured until O2S2 shows lean.

Fault criteria:
Too short time to O2S2 shows lean, indicating that the catalytic converter's oxygen storing ability is poor.

Depenent
None

System reaction to a fault:
None

OK report:
Diagnostics carried out without fault reported.

Fault handling:
Type III
(See Description of On-Board Diagnostics/Fault handling III, "Other emission-related components and functions" for more information.)

Diagnostic help

Diagnosis regards:
Faulty catalytic converter.

Functions in the diagnostic tool related to the fault:
Test value:
- O2S 1
- O2S 2
- Catalytic converter temperature.