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Home >> Lexus >> 2024 >> TX 350 Base, FWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 103 (Engine Control System - Diagnostic Codes (4 Of 7)) >> SFI SYSTEM (for 1Motor-HEV Model) >> DTC P0420-00: Catalyst System Efficiency Below Threshold Bank 1 [09/2023 - ] >> Procedure

DTC P0420-00: Catalyst System Efficiency Below Threshold Bank 1 [09/2023 - ]: Procedure

WARNING: This page is about a different car, the 2024 Lexus TX 500h. However, it is still accessible from the selected car via links, so may be relevant.
  1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0420-00) 
    1. Read the DTCs.

      Powertrain > Engine > Trouble Codes 

      Result

      Result Proceed to
      P0420-00 and other DTCs are output A
      P0420-00 is output B

      HINT: 

      If any DTCs other than P0420-00 are output, troubleshoot those DTCs first.

    Result: 

    GO TO DTC CHART. Refer to  DIAGNOSTIC TROUBLE CODE CHART [09/2023 - ] 

    Result: 

    See step  2

  2. READ FREEZE FRAME DATA (LONG FT B1S2) 
    1. Using the GTS, read the value displayed in the Freeze Frame Data.

      Powertrain > Engine > DTC(P0420-00) > Freeze Frame Data 

      Tester Display
      Long FT B1S2

      Result

      GTS Display Result Proceed to
      Long FT B1S2 Less than 1.0% A
      1.0% or higher B

    Result: 

    See step  82

    Result: 

    See step  3

  3. PERFORM ACTIVE TEST USING GTS (CONTROL THE INJECTION VOLUME FOR A/F SENSOR) 

    Pre-procedure1

    • Put the engine in Inspection Mode (for measuring Exhaust Gas).

      Powertrain > Hybrid Control > Utility 

      Tester Display
      Inspection Mode
    • Start the engine and warm it up until the engine coolant temperature is 80°C (176°F) or higher.
    • Warm up the air fuel ratio sensors at an engine speed of 2500 rpm for 90 seconds.
    • Change the fuel injection volume using the GTS, and monitor the output current of the air fuel ratio sensor (sensor 1) (A/F (O2) Sensor Current B1S1) and air fuel ratio sensor (sensor 2) (A/F (O2) Sensor Current B1S2) displayed on the GTS.

      Powertrain > Engine > Active Test 

      Active Test Display
      Control the Injection Volume for A/F Sensor
      Data List Display
      Injection Volume
      A/F (O2) Sensor Current B1S1
      A/F (O2) Sensor Current B1S2

      HINT: 

      • The Active Test "Control the Injection Volume for A/F Sensor" can be used to lower the fuel injection volume by 12.5% or increase the injection volume by 12.5%.
      • The air fuel ratio sensor (sensor 1) is displayed as A/F (O2) Sensor Current B1S1, and the air fuel ratio sensor (sensor 2) is displayed as A/F (O2) Sensor Current B1S2 on the GTS.
      • The air fuel ratio sensor (sensor 1) has an output delay of a few seconds and the air fuel ratio sensor (sensor 2) has a maximum output delay of approximately 20 seconds.
      • If the sensor output current does not change (almost no reaction) while performing the Active Test, the sensor may be malfunctioning.

      Standard

      GTS Display
      (Sensor)
      Injection Volume Status Current
      A/F (O2) Sensor Current B1S1
      (Air fuel ratio (sensor 1))
      12.5% Rich Below -0.075 mA
      -12.5% Lean More than 0.037 mA
      A/F (O2) Sensor Current B1S2
      (Air fuel ratio (sensor 2))
      12.5% Rich Below -0.86 mA
      -12.5% Lean More than 0.33 mA

      Result

      Status A/F (O2) Sensor Current B1S1 Status A/F (O2) Sensor Current B1S2 Actual air fuel ratio, air fuel ratio sensor (sensor 1) and air fuel ratio sensor (sensor 2) condition Main Suspected Trouble Area Proceed to
      Lean/Rich Lean/Rich Normal
      • Three-way catalytic converter
      • Gas leak from exhaust system
      A
      Lean Lean/Rich Air fuel ratio sensor (sensor 1) malfunction
      • Air fuel ratio sensor (sensor 1)
      B
      Rich Lean/Rich Air fuel ratio sensor (sensor 1) malfunction
      • Air fuel ratio sensor (sensor 1)
      Lean/Rich Lean Air fuel ratio sensor (sensor 2) malfunction
      • Air fuel ratio sensor (sensor 2)
      • Gas leak from exhaust system
      C
      Lean/Rich Rich Air fuel ratio sensor (sensor 2) malfunction
      • Air fuel ratio sensor (sensor 2)
      • Gas leak from exhaust system
      Lean Lean Actual air fuel ratio lean
      • Extremely lean actual air fuel ratio
      • Gas leak from exhaust system
      D
      Rich Rich Actual air fuel ratio rich
      • Extremely rich actual air fuel ratio
      • Gas leak from exhaust system
      1. Lean: During the Control the Injection Volume for A/F Sensor Active Test, the air fuel ratio sensor (sensor 1) output current (A/F (O2) Sensor Current B1S1) is consistently more than 0.037 mA, and the air fuel ratio sensor (sensor 2) output current (A/F (O2) Sensor Current B1S2) is consistently more than 0.33 mA.
      2. Rich: During the Control the Injection Volume for A/F Sensor Active Test, the air fuel ratio sensor (sensor 1) output current (A/F (O2) Sensor Current B1S1) is consistently below -0.075 mA, and the air fuel ratio sensor (sensor 2) output current (A/F (O2) Sensor Current B1S2) is consistently below -0.86 mA.
      3. Lean/Rich: During the Control the Injection Volume for A/F Sensor Active Test, the output current of the air fuel ratio sensor (sensor 1) or air fuel ratio sensor (sensor 2) alternate correctly.

      HINT: 

      Refer to "Data List / Active Test" [A/F (O2) Sensor Current B1S1, A/F (O2) Sensor Current B1S2].

      Refer to DATA LIST / ACTIVE TEST [09/2023 - ]

    Post-procedure1

    • None

    Result: 

    See step  5

    Result: 

    See step  6

    Result: 

    See step  8

    Result: 

    See step  4

  4. CHECK FOR EXHAUST GAS LEAK 
    1. Check for exhaust gas leaks.

      OK

      No gas leaks in exhaust system.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    See step  81

    Result: 

    NG 

    See step  78

  5. REPLACE AIR FUEL RATIO SENSOR (SENSOR 1) 

    HINT: 

    Refer to REMOVAL [09/2023 - ]

    Result

    Proceed to
    NEXT

    Result: 

    NEXT 

    See step  79

  6. CHECK FOR EXHAUST GAS LEAK 
    1. Check for exhaust gas leaks.

      OK

      No gas leaks in exhaust system.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  78

    Result: 

    OK 

    See step  7

  7. REPLACE AIR FUEL RATIO SENSOR (SENSOR 2) 

    HINT: 

    Refer to REMOVAL [09/2023 - ]

    Result

    Proceed to
    NEXT

    Result: 

    NEXT 

    See step  79

  8. CHECK FOR EXHAUST GAS LEAK 
    1. Check for exhaust gas leaks.

      OK

      No gas leaks in exhaust system.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  78

    Result: 

    OK 

    See step  9

  9. PERFORM ACTIVE TEST USING GTS (CONTROL THE INJECTION MODE) 

    Refer to PROCEDURE - Step 2

    Result

    Item Proceed to
    Port Direct
    OK OK A
    OK NG B
    NG OK C
    NG NG D

    Result: 

    See step  13

    Result: 

    See step  26

    Result: 

    See step  29

    Result: 

    See step  10

  10. CHECK IF VEHICLE HAS RUN OUT OF FUEL IN PAST 

    Refer to PROCEDURE - Step 3

    Result

    Result Proceed to
    YES A
    NO B

    Result: 

    See step  12

    Result: 

    See step  11

  11. DTC CAUSED BY RUNNING OUT OF FUEL 
    1. DTC caused by running out of fuel.

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  79

  12. CHECK FOR INTERMITTENT PROBLEMS 

    HINT: 

    Refer to HOW TO PROCEED WITH TROUBLESHOOTING [09/2023 - ]

    Result

    Proceed to
    NEXT

    Result: 

    NEXT 

    See step  79

  13. READ VALUE USING GTS (FUEL PRESSURE (HIGH)) 

    Refer to PROCEDURE - Step 4

    Result

    Result Proceed to
    The value of Fuel Pressure (High) is between 2000 and 32000 kPag A
    None of the above conditions are met B

    Result: 

    See step  20

    Result: 

    See step  14

  14. PERFORM ACTIVE TEST USING GTS (CONTROL THE INJECTION MODE (DIRECT)) 

    Refer to PROCEDURE - Step 5

    Result

    Item Proceed to
    Injection Mode High Pressure Fuel Pump Duty Ratio (D4) Total of Short FT B1S1 and Long FT B1S1
    Direct 10% to 50% - A
    50% or higher -20% or less B
    10% or less +20% or higher
    50% or higher +20% or higher C
    10% or less -20% or less D

    Result: 

    See step  18

    Result: 

    See step  21

    Result: 

    See step  19

    Result: 

    See step  15

  15. PERFORM ACTIVE TEST USING GTS (CONTROL THE INJECTION MODE (DIRECT)) 

    Refer to PROCEDURE - Step 6

    Result

    Item Proceed to
    Injection Mode High Pressure Fuel Pump Duty Ratio (D4) Total of Short FT B1S1 and Long FT B1S1
    Direct 10 to 50% -25% or less A
    10 to 50% +25% or higher
    10 to 50% -25 to +25% B

    Result: 

    See step  17

    Result: 

    See step  16

  16. REPLACE DIRECT FUEL INJECTOR ASSEMBLY 

    HINT: 

    Refer to REMOVAL [09/2023 - ]

    Result

    Proceed to
    NEXT

    Result: 

    NEXT 

    See step  79

  17. CHECK FOR INTERMITTENT PROBLEMS 

    HINT: 

    Refer to HOW TO PROCEED WITH TROUBLESHOOTING [09/2023 - ]

    Result

    Proceed to
    NEXT

    Result: 

    NEXT 

    See step  79

  18. REPLACE FUEL PRESSURE SENSOR (FOR HIGH PRESSURE SIDE) 

    HINT: 

    Refer to REMOVAL [09/2023 - ]

    Result

    Proceed to
    NEXT

    Result: 

    NEXT 

    See step  79

  19. REPLACE ECM 

    HINT: 

    Refer to REMOVAL [09/2023 - ]

    Result

    Proceed to
    NEXT

    Result: 

    NEXT 

    See step  79

  20. CHECK MISFIRE COUNT OF DIRECT INJECTION 

    Refer to PROCEDURE - Step 7

    Result

    Injection Mode Misfire Count Proceed to
    Direct No misfire counts, or misfire counts occur randomly in all cylinders A
    Misfire counts occur in particular cylinder B

    Result: 

    See step  24

    Result: 

    See step  21

  21. REPLACE FUEL (ENGINE ROOM SIDE) PUMP ASSEMBLY (FOR HIGH PRESSURE SIDE) 

    Refer to PROCEDURE - Step 8

    Result

    Proceed to
    NEXT

    Result: 

    NEXT 

    See step  22

  22. CLEAR DTC 

    Pre-procedure1

    • None
    • Clear the DTCs.

      Powertrain > Engine > Clear DTCs 

      Result

      Proceed to
      NEXT

    Post-procedure1

    • Turn the ignition switch off and wait for at least 30 seconds.

    Result: 

    NEXT 

    See step  23

  23. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED 

    Pre-procedure1

    • Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
    • Read the DTCs.

      Powertrain > Engine > Trouble Codes 

      Result

      Result Proceed to
      DTCs are not output A
      P0420-00 is output B

    Post-procedure1

    • None

    Result: 

    END 

    Result: 

    See step  25

  24. REPLACE DIRECT FUEL INJECTOR ASSEMBLY 

    HINT: 

    Refer to REMOVAL [09/2023 - ]

    Result

    Proceed to
    NEXT

    Result: 

    NEXT 

    See step  79

  25. REPLACE ECM 

    HINT: 

    Refer to REMOVAL [09/2023 - ]

    Result

    Proceed to
    NEXT

    Result: 

    NEXT 

    See step  79

  26. INSPECT PORT FUEL INJECTOR ASSEMBLY 

    Refer to PROCEDURE - Step 11

    Result

    Proceed to
    OK
    NG

    Result: 

    NG 

    See step  28

    Result: 

    OK 

    See step  27

  27. REPLACE ECM 

    HINT: 

    Refer to REMOVAL [09/2023 - ]

    Result

    Proceed to
    NEXT

    Result: 

    NEXT 

    See step  79

  28. REPLACE PORT FUEL INJECTOR ASSEMBLY 

    HINT: 

    Refer to REMOVAL [09/2023 - ]

    Result

    Proceed to
    NEXT

    Result: 

    NEXT 

    See step  79

  29. INSPECT PURGE VSV 

    Refer to PROCEDURE - Step 12

    Result

    Proceed to
    OK
    NG

    Result: 

    NG 

    See step  77

    Result: 

    OK 

    See step  30

  30. CHECK HARNESS AND CONNECTOR (PURGE VSV - ECM) 

    Refer to PROCEDURE - Step 13

    Result

    Proceed to
    OK
    NG

    Result: 

    NG 

    See step  76

    Result: 

    OK 

    See step  31

  31. CHECK PCV VALVE AND HOSE CONNECTIONS 

    Refer to PROCEDURE - Step 14

    Result

    Proceed to
    OK
    NG

    Result: 

    NG 

    See step  75

    Result: 

    OK 

    See step  32

  32. CHECK INTAKE SYSTEM 

    Refer to PROCEDURE - Step 15

    Result

    Proceed to
    OK
    NG

    Result: 

    NG 

    See step  74

    Result: 

    OK 

    See step  33

  33. PERFORM ACTIVE TEST USING GTS (CONTROL THE INJECTION VOLUME FOR A/F SENSOR) 

    Refer to PROCEDURE - Step 16

    Result

    Status A/F (O2) Sensor Current B1S1 Status A/F (O2) Sensor Current B1S2 Air Fuel Ratio Condition and Air Fuel Ratio Sensor Condition Suspected Trouble Area Proceed to
    Lean/Rich Lean/Rich Normal - A
    Lean Lean Actual air fuel ratio lean
    • PCV valve and hose
    • PCV hose connections
    • Gas leak from exhaust system
    • Intake system
    • Fuel pressure
    • Mass air flow meter sub-assembly
    • Engine coolant temperature sensor
    Rich Rich Actual air fuel ratio rich
    • Gas leak from exhaust system
    • Ignition system
    • Fuel pressure
    • Mass air flow meter sub-assembly
    • Engine coolant temperature sensor
    Lean Lean/Rich Air fuel ratio sensor (sensor 1) malfunction
    • Air fuel ratio sensor (sensor 1)
    B
    Rich Lean/Rich Air fuel ratio sensor (sensor 1) malfunction
    • Air fuel ratio sensor (sensor 1)

    Result: 

    See step  47

    Result: 

    See step  34

  34. READ VALUE USING GTS (COOLANT TEMPERATURE SENSOR1, COOLANT TEMPERATURE SENSOR2) 

    Refer to PROCEDURE - Step 17

    Result

    Result Proceed to
    OK A
    NG (Coolant Temperature Sensor1) B
    NG (Coolant Temperature Sensor2) C

    Result: 

    See step  45

    Result: 

    See step  46

    Result: 

    See step  35

  35. READ VALUE USING GTS (MASS AIR FLOW SENSOR) 

    Refer to PROCEDURE - Step 18

    Result

    Result Proceed to
    The value of Mass Air Flow Sensor is between 5 and 15 gm/sec A
    None of the above conditions are met B

    Result: 

    See step  55

    Result: 

    See step  36

  36. CHECK FUEL PRESSURE (FOR LOW PRESSURE SIDE) 

    Refer to PROCEDURE - Step 19

    Result

    Proceed to
    OK
    NG

    Result: 

    NG 

    See step  42

    Result: 

    OK 

    See step  37

  37. CHECK FOR EXHAUST GAS LEAK 

    Refer to PROCEDURE - Step 20

    Result

    Proceed to
    OK
    NG

    Result: 

    NG 

    See step  41

    Result: 

    OK 

    See step  38

  38. INSPECT SPARK PLUG 

    Refer to PROCEDURE - Step 21

    Result

    Proceed to
    OK
    NG

    Result: 

    NG 

    See step  40

    Result: 

    OK 

    See step  39

  39. CHECK FOR SPARK (SPARK TEST) 

    Refer to PROCEDURE - Step 22

    Result

    Proceed to
    NEXT

    Result: 

    NEXT 

    See step  55

  40. REPLACE SPARK PLUG 

    HINT: 

    Refer to REMOVAL [09/2023 - ]

    Result

    Proceed to
    NEXT

    Result: 

    NEXT 

    See step  79

  41. REPAIR OR REPLACE EXHAUST SYSTEM 
    1. Repair or replace exhaust system.

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  79

  42. CHECK FUEL LINE 

    Refer to PROCEDURE - Step 23

    Result

    Proceed to
    OK
    NG

    Result: 

    NG 

    See step  44

    Result: 

    OK 

    See step  43

  43. GO TO FUEL PUMP CONTROL CIRCUIT 

    HINT: 

    Refer to Fuel Pump Control Circuit [09/2023 - ]

    Result

    Proceed to
    NEXT

    Result: 

    NEXT 

    See step  79

  44. REPAIR OR REPLACE FUEL SYSTEM 
    1. Repair or replace fuel system.

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  79

  45. REPLACE ENGINE COOLANT TEMPERATURE SENSOR (FOR OUTLET SIDE) 

    HINT: 

    Refer to REMOVAL [09/2023 - ]

    Result

    Proceed to
    NEXT

    Result: 

    NEXT 

    See step  79

  46. REPLACE ENGINE COOLANT TEMPERATURE SENSOR (FOR CYLINDER HEAD SIDE) 

    HINT: 

    Refer to REMOVAL [09/2023 - ]

    Result

    Proceed to
    NEXT

    Result: 

    NEXT 

    See step  79

  47. INSPECT AIR FUEL RATIO SENSOR (SENSOR 1) (HEATER RESISTANCE) 

    Refer to PROCEDURE - Step 24

    Result

    Proceed to
    OK
    NG

    Result: 

    NG 

    See step  73

    Result: 

    OK 

    See step  48

  48. CHECK TERMINAL VOLTAGE (POWER SOURCE OF AIR FUEL RATIO SENSOR (SENSOR 1)) 

    Refer to PROCEDURE - Step 25

    Result

    Proceed to
    OK
    NG

    Result: 

    NG 

    See step  58

    Result: 

    OK 

    See step  49

  49. CHECK HARNESS AND CONNECTOR (AIR FUEL RATIO SENSOR (SENSOR 1) - ECM) 

    Refer to PROCEDURE - Step 26

    Result

    Proceed to
    OK
    NG

    Result: 

    NG 

    See step  53

    Result: 

    OK 

    See step  50

  50. REPLACE AIR FUEL RATIO SENSOR (SENSOR 1) 

    Refer to PROCEDURE - Step 27

    Result

    Proceed to
    NEXT

    Result: 

    NEXT 

    See step  51

  51. CLEAR DTC 

    Pre-procedure1

    • None
    • Clear the DTCs.

      Powertrain > Engine > Clear DTCs 

      Result

      Proceed to
      NEXT

    Post-procedure1

    • Turn the ignition switch off and wait for at least 30 seconds.

    Result: 

    NEXT 

    See step  52

  52. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED 

    Pre-procedure1

    • Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
    • Read the DTCs.

      Powertrain > Engine > Trouble Codes 

      Result

      Result Proceed to
      DTCs are not output A
      P0420-00 is output B

    Post-procedure1

    • None

    Result: 

    END 

    Result: 

    See step  54

  53. REPAIR OR REPLACE HARNESS OR CONNECTOR 
    1. Repair or replace harness or connector.

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  79

  54. READ VALUE USING GTS (MASS AIR FLOW SENSOR) 

    Refer to PROCEDURE - Step 30

    Result

    Proceed to
    NEXT

    Result: 

    NEXT 

    See step  55

  55. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY CONNECTOR CONNECTION) 

    Refer to PROCEDURE - Step 31

    Result

    Proceed to
    NEXT

    Result: 

    NEXT 

    See step  56

  56. CLEAR DTC 

    Pre-procedure1

    • None
    • Clear the DTCs.

      Powertrain > Engine > Clear DTCs 

      Result

      Proceed to
      NEXT

    Post-procedure1

    • Turn the ignition switch off and wait for at least 30 seconds.

    Result: 

    NEXT 

    See step  57

  57. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED 

    Pre-procedure1

    • Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
    • Read the DTCs.

      Powertrain > Engine > Trouble Codes 

      Result

      Result Proceed to
      DTCs are not output A
      P0420-00 is output B

    Post-procedure1

    • None

    Result: 

    See step  79

    Result: 

    See step  63

  58. INSPECT EFI-MAIN NO. 3 RELAY 

    Refer to PROCEDURE - Step 34

    Result

    Proceed to
    OK
    NG

    Result: 

    NG 

    See step  72

    Result: 

    OK 

    See step  59

  59. CHECK TERMINAL VOLTAGE (POWER SOURCE OF EFI-MAIN NO. 3 RELAY) 

    Refer to PROCEDURE - Step 35

    Result

    Proceed to
    OK
    NG

    Result: 

    NG 

    See step  71

    Result: 

    OK 

    See step  60

  60. CHECK HARNESS AND CONNECTOR (EFI-MAIN NO. 3 RELAY - BODY GROUND) 

    Refer to PROCEDURE - Step 36

    Result

    Proceed to
    OK
    NG

    Result: 

    NG 

    See step  70

    Result: 

    OK 

    See step  61

  61. CHECK HARNESS AND CONNECTOR (EFI-MAIN NO. 3 RELAY - AIR FUEL RATIO SENSOR (SENSOR 1)) 

    Refer to PROCEDURE - Step 37

    Result

    Proceed to
    OK
    NG

    Result: 

    NG 

    See step  67

    Result: 

    OK 

    See step  62

  62. REPAIR OR REPLACE HARNESS OR CONNECTOR (EFI-MAIN NO. 1 RELAY - EFI-MAIN NO. 3 RELAY) 
    1. Repair or replace harness or connector (EFI-MAIN No. 1 relay - EFI-MAIN No. 3 relay)

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  79

  63. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY - ECM) 

    Refer to PROCEDURE - Step 38

    Result

    Proceed to
    OK
    NG

    Result: 

    NG 

    See step  68

    Result: 

    OK 

    See step  64

  64. INSPECT MASS AIR FLOW METER SUB-ASSEMBLY 

    Refer to PROCEDURE - Step 39

    Result

    Proceed to
    NEXT

    Result: 

    NEXT 

    See step  65

  65. CLEAR DTC 

    Pre-procedure1

    • None
    • Clear the DTCs.

      Powertrain > Engine > Clear DTCs 

      Result

      Proceed to
      NEXT

    Post-procedure1

    • Turn the ignition switch off and wait for at least 30 seconds.

    Result: 

    NEXT 

    See step  66

  66. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED 

    Pre-procedure1

    • Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
    • Read the DTCs.

      Powertrain > Engine > Trouble Codes 

      Result

      Result Proceed to
      DTCs are not output A
      P0420-00 is output B

    Post-procedure1

    • None

    Result: 

    END 

    Result: 

    See step  69

  67. REPAIR OR REPLACE HARNESS OR CONNECTOR 
    1. Repair or replace harness or connector.

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  79

  68. REPAIR OR REPLACE HARNESS OR CONNECTOR 
    1. Repair or replace harness or connector.

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  79

  69. REPLACE ECM 

    HINT: 

    Refer to REMOVAL [09/2023 - ]

    Result

    Proceed to
    NEXT

    Result: 

    NEXT 

    See step  79

  70. REPAIR OR REPLACE HARNESS OR CONNECTOR 
    1. Repair or replace harness or connector.

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  79

  71. REPAIR OR REPLACE HARNESS OR CONNECTOR (AUXILIARY BATTERY - EFI-MAIN NO. 3 RELAY) 
    1. Repair or replace harness or connector (auxiliary battery - EFI-MAIN No. 3 relay)

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  79

  72. REPLACE EFI-MAIN NO. 3 RELAY 
    1. Replace EFI-MAIN No. 3 relay.

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  79

  73. REPLACE AIR FUEL RATIO SENSOR (SENSOR 1) 

    HINT: 

    Refer to REMOVAL [09/2023 - ]

    Result

    Proceed to
    NEXT

    Result: 

    NEXT 

    See step  79

  74. REPAIR OR REPLACE INTAKE SYSTEM 
    1. Repair or replace intake system.

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  79

  75. REPAIR OR REPLACE PCV VALVE OR HOSE 
    1. Repair or replace pcv valve or hose.

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  79

  76. REPAIR OR REPLACE HARNESS OR CONNECTOR 
    1. Repair or replace harness or connector.

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  79

  77. REPLACE PURGE VSV 

    HINT: 

    Refer to REMOVAL [09/2023 - ]

    Result

    Proceed to
    NEXT

    Result: 

    NEXT 

    See step  79

  78. REPAIR OR REPLACE EXHAUST SYSTEM 
    1. Repair or replace exhaust system.

      HINT: 

      Perform "Inspection After Repair" after repairing or replacing the exhaust system.

      Refer to INITIALIZATION [09/2023 - ]

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  79

  79. CLEAR DTC 

    Pre-procedure1

    • None
    • Clear the DTCs.

      Powertrain > Engine > Clear DTCs 

      Result

      Proceed to
      NEXT

    Post-procedure1

    • Turn the ignition switch off and wait for at least 30 seconds.

    Result: 

    NEXT 

    See step  80

  80. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED 

    Pre-procedure1

    • Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
    • Read the DTCs.

      Powertrain > Engine > Trouble Codes 

      Result

      Result Proceed to
      DTCs are not output A
      P0420-00 is output B

    Post-procedure1

    • None

    Result: 

    END 

    Result: 

    See step  81

  81. REPLACE CONVERTER WITH CATALYST ASSEMBLY (TWC: FRONT CATALYST AND REAR CATALYST) 

    HINT: 

    Refer to REMOVAL [09/2023 - ]

    Result

    Proceed to
    NEXT

    Result: 

    NEXT 

    END 

  82. CHECK FOR EXHAUST GAS LEAK 

    OK

    No gas leaks in exhaust system.

    HINT: 

    Perform "Inspection After Repair" after repairing or replacing the exhaust system.

    Refer to INITIALIZATION [09/2023 - ]

    Result

    Proceed to
    OK
    NG

    Result: 

    NG 

    REPAIR OR REPLACE EXHAUST SYSTEM 

    Result: 

    OK 

    See step  83

  83. REPLACE AIR FUEL RATIO SENSOR (SENSOR 2) 

    HINT: 

    Refer to REMOVAL [09/2023 - ]

    Result

    Proceed to
    NEXT

    Result: 

    NEXT 

    See step  84

  84. CLEAR DTC 

    Pre-procedure1

    • None
    • Clear the DTCs.

      Powertrain > Engine > Clear DTCs 

      Result

      Proceed to
      NEXT

    Post-procedure1

    • Turn the ignition switch off and wait for at least 30 seconds.

    Result: 

    NEXT 

    See step  85

  85. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED 

    Pre-procedure1

    • Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
    • Check for DTCs.

      Powertrain > Engine > Trouble Codes 

      Result

      DTCs are not output.

      Result

      Proceed to
      NEXT

    Post-procedure1

    • None

    Result: 

    NEXT 

    END