DTC P0420 - Catalyst System Efficiency Below Threshold (Bank 1) -
WARNING: This page is about a different variant/trim than selected.
- DTC DETECTING CONDITION:
- Two consecutive driving cycles with malfunction
- TROUBLE SYMPTOM:
- Engine stalls.
- Idle mixture is out of specifications.
CAUTION:
After repair or replacement of malfunctioning parts, conduct Clear Memory Mode < Ref. to
OPERATION , CLEAR MEMORY MODE > and INSPECTION MODE < Ref. to
OPERATION , INSPECTION MODE. >
- WIRING DIAGRAM:
DIAGNOSTIC PROCEDURE
| Step | Check | Yes | No |
|---|---|---|---|
| 1 CHECK ANY OTHER DTC ON DISPLAY. | Is any other DTC displayed? | Inspect the relevant DTC using "List of Diagnostic Trouble Code (DTC)". < Ref. to
LIST OF DIAGNOSTIC TROUBLE CODE (DTC) . >
NOTE:
In this case, it is not necessary to inspect DTC P0420.
|
Go to step 2. |
| 2 CHECK EXHAUST SYSTEM. Check for gas leaks or air suction caused by loose or dislocated nuts and bolts, and open hole at exhaust pipes.
NOTE:
Check the following positions.
|
Is there any fault in exhaust system? | Repair or replace exhaust system. < Ref. to GENERAL DESCRIPTION . > | Go to step 3. |
| 3 CHECK CATALYTIC CONVERTER. | Is there any damage at catalyst? | Replace front catalytic converter. < Ref. to FRONT CATALYTIC CONVERTER . > | Go to step 4. |
4 CHECK REAR OXYGEN SENSOR CIRCUIT.
|
Is the measured value less than 1 Ω? | Go to step 5. | Repair open harness between ECM and rear oxygen sensor. |
| 5 CHECK SEALED WIRE. | Is the sealed wire connected? | Contact with SOA service center.
NOTE:
Inspection by DTM is required, because probable cause is deterioration of multiple parts.
|
Repair sealed wire. |