P0420

P0420 00

Three Way Catalytic Converter. Malfunction.







Fault symptom
- Check Engine (OBDII, 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 < 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 stabilised 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.

Dependent:
- None

System reaction to a fault:
- None

OK report:
- Diagnostics carried out without fault reported.

Fault handling:
Type III
(See section 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.