DTC P0420: Catalyst System Efficiency Below Threshold (Bank 1); DTC P0430: Catalyst System Efficiency Below Threshold (Bank 2) [08/2013 - ]: Procedure

1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON.
3. Turn the Techstream on.
4. Enter the following menus: Powertrain / Engine / 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.

B → See step   13 

A: Go to next step 

1. Connect the Techstream to the DLC3.
2. Start the engine and warm it up.
3. Turn the Techstream on.
4. Run the engine at an engine speed of 2500 rpm for approximately 90 seconds.
5. Enter the following menus: Powertrain / Engine / Active Test / Control the Injection Volume for A/F Sensor.
6. Perform the Active Test operation with the engine idling (press the -12.5% or 12.5% button to change the fuel injection volume).
7. Monitor the voltage outputs of the air fuel ratio and heated oxygen sensors (AFS Voltage B1S1 and O2S B1S2 or AFS Voltage B2S1 and O2S B2S2) displayed on the Techstream.

   HINT: 

   • The fuel injection volume can be changed to -12.5% or 12.5%.
   • 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	Less than 3.1 V
   AFS Voltage B1S1 or AFS Voltage B2S1 (Air fuel ratio)	-12.5%	Lean	More than 3.4 V
   O2S B1S2 or O2S B2S2 (Heated oxygen)	12.5%	Rich	More than 0.55 V
   O2S B1S2 or O2S B2S2 (Heated oxygen)	-12.5%	Lean	Less than 0.4 V

   RESULT
   
   

   Status AFS Voltage B1S1 or AFS Voltage B2S1	Status O2S B1S2 or O2S B2S2	Air Fuel Ratio Condition and Air Fuel Ratio and Heated Oxygen Sensor Condition	Misfire	Suspected Area	Proceed to
   Lean/Rich	Lean/Rich	Normal	-	Three-way catalytic converter Gas leaks 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	B
   Lean/Rich	Lean	Heated oxygen sensor malfunction	-	Heated oxygen sensor Gas leaks from exhaust system	C
   Lean/Rich	Rich	Heated oxygen sensor malfunction	-	Heated oxygen sensor Gas leaks from exhaust system	C
   Lean	Lean	Actual air fuel ratio lean	May occur	Extremely rich or lean actual air fuel ratio Gas leaks from exhaust system	D
   Rich	Rich	Actual air fuel ratio rich	-	Extremely rich or lean actual air fuel ratio Gas leaks from exhaust system	D

   Lean: During the Control the Injection Volume for A/F Sensor Active Test, the air fuel ratio sensor output voltage (AFS Voltage) is consistently more than 3.4 V, and the heated oxygen sensor output voltage (O2S) is consistently less than 0.4 V.

   Rich: During the Control the Injection Volume for A/F Sensor Active Test, the AFS Voltage is consistently less than 3.1 V, and the O2S is consistently more than 0.55 V.

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

B → See step   7 

C → See step   5 

D → See step   6 

A: Go to next step 

1. Inspect for exhaust gas leaks from the exhaust manifold sub-assembly and exhaust pipes.

   OK

   No gas leaks.

NG → See step   8 

OK: Go to next step 

HINT: 

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

1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON.
3. Turn the Techstream on.
4. Enter the following menus: Powertrain / Engine / Trouble Codes.
5. Read the DTCs.
   RESULT
   
   

   Result	Vehicle Type	Proceed to
   P0420	2WD	A, C
   	4WD	A, D
   P0430	2WD	B, C
   	4WD	B, D
   P0420 and P0430	2WD	A, B, C
   	4WD	A, B, D

A → See step   14 

B → See step   15 

C → See step   16 

D → See step   17 

1. Check for exhaust gas leaks.

   OK

   No gas leaks.

OK → See step   9 

NG → See step   8 

1. Check for exhaust gas leaks.

   OK

   No gas leaks.

OK → See step   10 

NG → See step   8 

1. Replace the air fuel ratio sensor. Refer to REMOVAL [08/2013 - ] .

NEXT → See step   11 

1. Repair or replace exhaust gas leak point.

NEXT → See step   11 

1. Replace the heated oxygen sensor. Refer to REMOVAL [08/2013 - ] .

NEXT → See step   11 

1. Check the cause of extremely rich or lean actual air fuel ratio, referring to the DTC P0171 Inspection Procedure. Refer to INSPECTION PROCEDURE .

NEXT: Go to next step 

1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON.
3. Turn the Techstream on.
4. Clear the DTCs. Refer to DTC CHECK / CLEAR [08/2013 - ] .
5. Turn the ignition switch off and wait for at least 30 seconds.
6. Start the engine.
7. Turn the Techstream on.
8. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
9. Enter the following menus: Powertrain / Engine / Trouble Codes.
10. Read the pending DTCs.
    RESULT
    
    

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

B → END 

A: Go to next step 

HINT: 

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

1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON.
3. Turn the Techstream on.
4. Enter the following menus: Powertrain / Engine / Trouble Codes.
5. Read the DTCs.
   RESULT
   
   

   Result	Vehicle Type	Proceed to
   P0420	2WD	A, C
   	4WD	A, D
   P0430	2WD	B, C
   	4WD	B, D
   P0420 and P0430	2WD	A, B, C
   	4WD	A, B, D

A → See step   14 

B → See step   15 

C → See step   16 

D → See step   17