DTC P0420: Catalyst System Efficiency Below Threshold (Bank 1); DTC P0430: Catalyst System Efficiency Below Threshold (Bank 2) [09/2014 - 10/2015]: Procedure

1. Connect the Techstream to the DLC3.
2. Turn the power switch on (IG).
3. Turn the Techstream on.
4. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
5. Read the DTCs.

   Result

   Result	Proceed to
   DTC P0420 and/or P0430 are output	A
   DTC P0420 and/or P0430 and other DTCs are output	B

   HINT: 

   If any DTCs other than P0420 or P0430 are output, troubleshoot those DTCs first.

Result:  B

B 

GO TO DTC CHART 

(See servic information).Refer to DIAGNOSTIC TROUBLE CODE CHART [09/2014 - 10/2015] )

Result:  A

A 

See step  2

1. Connect the Techstream to the DLC3.
2. Turn the power switch on (IG).
3. Turn the Techstream on.
4. Put the engine in inspection mode (maintenance mode) (See servic information).Refer to INSPECTION MODE PROCEDURE [09/2014 - 10/2015] ).
5. Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or more.
6. Idle the engine for 5 minutes or more with the shift lever in P.
7. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor / AFS Voltage B1S1 and O2S B1S2 or AFS Voltage B2S1 and O2S B2S2.
8. Perform the Active Test operation with the engine idling (press the RIGHT or LEFT button to change the fuel injection volume).
9. Monitor the voltage outputs of the air fuel ratio sensor and heated oxygen sensor (AFS Voltage B1S1 and O2S B1S2 or AFS Voltage B2S1 and O2S B2S2) displayed on the Techstream.

   HINT: 

   • Change the fuel injection volume within the range of - 12.5% to +12.5%. The injection volume can be changed in fine gradations.
   • Each sensor reacts in accordance with increases and decreases in the fuel injection volume.
   • The air fuel ratio sensor has an output delay of a few seconds and the heated oxygen sensor has a maximum output delay of approximately 20 seconds.
   • If the sensor output voltage does not change (almost no reaction) while performing the Active Test, the sensor may be malfunctioning.

   Standard

   Techstream Display (Sensor)	Injection Volume	Status	Voltage
   AFS Voltage B1S1 or AFS Voltage B2S1 (Air fuel ratio)	+12.5%	Rich	Below 3.1 V
   	-12.5%	Lean	Higher than 3.4 V
   O2S B1S2 or O2S B2S2 (Heated oxygen)	+12.5%	Rich	Higher than 0.55 V
   	-12.5%	Lean	Below 0.4 V

   Result

   Status AFS Voltage B1S1 or AFS Voltage B2S1	Status O2S B1S2 or O2S B2S2	A/F Condition and A/F and HO2 Sensor Conditions	Main Suspected Trouble Areas	Proceed to
   Lean/Rich	Lean/Rich	Normal	Three-Way Catalytic Converter (TWC) Gas leakage from exhaust system	A
   Lean	Lean/Rich	Air fuel ratio sensor malfunction	Air fuel ratio sensor	B
   Rich	Lean/Rich	Air fuel ratio sensor malfunction	Air fuel ratio sensor
   Lean/Rich	Lean	Heated oxygen sensor malfunction	Heated oxygen sensor Gas leakage from exhaust system	C
   Lean/Rich	Rich	Heated oxygen sensor malfunction	Heated oxygen sensor Gas leakage from exhaust system
   Lean	Lean	Actual air-fuel ratio lean	Extremely rich or lean actual air-fuel ratio Gas leakage from exhaust system	D
   Rich	Rich	Actual air-fuel ratio lean	Extremely rich or lean actual air-fuel ratio Gas leakage from exhaust system

   Lean: During Control the Injection Volume for A/F Sensor, the air fuel ratio sensor output voltage (AFS Voltage B1S1 or AFS Voltage B2S1) is consistently higher than 3.4 V, and the heated oxygen sensor output voltage (O2S B1S2 or O2S B2S2) is consistently below 0.4 V.

   Rich: During Control the Injection Volume for A/F Sensor, the AFS Voltage B1S1 or AFS Voltage B2S1 is consistently below 3.1 V, and the O2S B1S2 or O2S B2S2 is consistently higher than 0.55 V.

   Lean/Rich: During Control the Injection Volume for A/F Sensor of the Active Test, the output voltage of the air fuel ratio sensor and heated oxygen sensor alternate correctly.

Result:  B

B 

See step  7

Result:  C

C 

See step  5

Result:  D

D 

See step  6

Result:  A

A 

See step  3

1. Check for exhaust gas leaks.

   OK

   No gas leaks.

   HINT: 

   Perform "Inspection After Repair" after repairing or replacing the exhaust system (See servic information).Refer to INITIALIZATION [09/2014 - ] ).

Result:  NG

NG 

See step  8

Result:  OK

OK 

See step  4

HINT: 

Confirm the replacement parts, referring to the illustration in the Catalyst Location.

1. Connect the Techstream to the DLC3.
2. Turn the power switch on (IG).
3. Turn the Techstream on.
4. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
5. Read the DTCs.

   Result

   Result	Proceed to
   DTC P0420 is output	A, C
   DTC P0430 is output	B, C
   DTC P0420 and P0430 are output	A, B, C

Result:  C

C 

REPLACE FRONT EXHAUST PIPE ASSEMBLY (TWC: REAR CATALYST) 

(See servic information).Refer to REMOVAL [09/2014 - ] )

Result:  A

A 

REPLACE EXHAUST MANIFOLD SUB-ASSEMBLY RH (TWC: FRONT CATALYST) 

(See servic information).Refer to REMOVAL [09/2014 - ] )

Result:  B

B 

REPLACE EXHAUST MANIFOLD SUB-ASSEMBLY LH (TWC: FRONT CATALYST) 

(See servic information).Refer to REMOVAL [09/2014 - ] )

1. Check for exhaust gas leaks.

   OK

   No gas leaks.

   HINT: 

   Perform "Inspection After Repair" after repairing or replacing the exhaust system (See servic information).Refer to INITIALIZATION [09/2014 - ] ).

Result:  OK

OK 

See step  9

Result:  NG

NG 

See step  8

1. Check for exhaust gas leaks.

   OK

   No gas leaks.

   HINT: 

   Perform "Inspection After Repair" after repairing or replacing the exhaust system (See servic information).Refer to INITIALIZATION [09/2014 - ] ).

Result:  OK

OK 

See step  10

Result:  NG

NG 

See step  8

1. Replace the air fuel ratio sensor (See servic information).Refer to REMOVAL [09/2014 - ] ).

   HINT: 

   Perform "Inspection After Repair" after replacing the air fuel ratio sensor (See servic information).Refer to INITIALIZATION [09/2014 - ] ).

Result:  NEXT

NEXT 

See step  11

1. Repair or replace exhaust gas leak point.

   HINT: 

   Perform "Inspection After Repair" after repairing or replacing the exhaust system (See servic information).Refer to INITIALIZATION [09/2014 - ] ).

Result:  NEXT

NEXT 

See step  11

1. Replace the heated oxygen sensor (See servic information).Refer to REMOVAL [09/2014 - ] ).

   HINT: 

   Perform "Inspection After Repair" after replacing the heated oxygen sensor (See servic information).Refer to INITIALIZATION [09/2014 - ] ).

Result:  NEXT

NEXT 

See step  11

1. Check the cause of extremely rich or lean actual air fuel ratio, referring to the DTC P0171 Inspection Procedure (See servic information).Refer to DTC P0171: System Too Lean (Bank 1); DTC P0172: System Too Rich (Bank 1); DTC P0174: System Too Lean (Bank 2); DTC P0175: System Too Rich (Bank 2); DTC P1170: Port Injector Fuel Performance; DTC P117B: Direct Injector Fuel Performance [09/2014 - 10/2015] ).

Result:  NEXT

NEXT 

See step  11

1. Connect the Techstream to the DLC3.
2. Turn the power switch on (IG).
3. Turn the Techstream on.
4. Clear the DTCs (See servic information).Refer to DTC CHECK / CLEAR [09/2014 - ] ).
5. Turn the power switch off and wait for at least 30 seconds.
6. Turn the power switch on (IG).
7. Turn the Techstream on.
8. Put the engine in inspection mode (maintenance mode) (See servic information).Refer to INSPECTION MODE PROCEDURE [09/2014 - 10/2015] ).
9. Start the engine.
10. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
11. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
12. Read the DTCs.

    Result

    Result	Proceed to
    DTC P0420 and/or P0430 is output	A
    DTC is not output	B

Result:  B

B 

END 

Result:  A

A 

See step  12

HINT: 

Confirm the replacement parts, referring to the illustration in the Catalyst Location.

1. Connect the Techstream to the DLC3.
2. Turn the power switch on (IG).
3. Turn the Techstream on.
4. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
5. Read the DTCs.

   Result

   Result	Proceed to
   DTC P0420 is output	A, C
   DTC P0430 is output	B, C
   DTC P0420 and P0430 are output	A, B, C

Result:  C

C 

REPLACE FRONT EXHAUST PIPE ASSEMBLY (TWC: REAR CATALYST) 

(See servic information).Refer to REMOVAL [09/2014 - ] )

Result:  A

A 

REPLACE EXHAUST MANIFOLD SUB-ASSEMBLY RH (TWC: FRONT CATALYST) 

(See servic information).Refer to REMOVAL [09/2014 - ] )

Result:  B

B 

REPLACE EXHAUST MANIFOLD SUB-ASSEMBLY LH (TWC: FRONT CATALYST) 

(See servic information).Refer to REMOVAL [09/2014 - ] )