DTC P0420-00: Catalyst System Efficiency Below Threshold Bank 1 [12/2018 - 08/2019]: Procedure

CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0420-00)

Connect the Techstream to the DLC3.
Turn the power switch on (IG).
Turn the Techstream on.
Enter the following menus: Powertrain / Engine / Trouble Codes.

Read the DTCs.

Powertrain > Engine > Trouble Codes

Result

Result	Proceed to
DTC P0420-00 is output	A
DTC P0420-00 and other DTCs are 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 [12/2018 - 08/2019]

Result:

See step 2

PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE INJECTION VOLUME FOR A/F SENSOR)

Connect the Techstream to the DLC3.
Turn the power switch on (IG).
Turn the Techstream on.

Put the engine in Inspection Mode (Maintenance Mode).

Powertrain > Hybrid Control > Utility

Tester Display
Inspection Mode

Start the engine and warm it up until the engine coolant temperature is 75°C (167°F) or higher.
Idle the engine for 5 minutes or more with park (P) selected.

Enter the following menus: Powertrain / Engine / Active Test / Control the Injection Volume for A/F Sensor / Data List / Injection Volume, A/F (O2) Sensor Voltage B1S1 and O2 Sensor Voltage B1S2.

Powertrain > Engine > Active Test

Active Test Display
Control the Injection Volume for A/F Sensor

Data List Display
Injection Volume
A/F (O2) Sensor Voltage B1S1
O2 Sensor Voltage B1S2

Change the fuel injection volume using the Techstream, and monitor the output voltage of the air fuel ratio sensor (A/F (O2) Sensor Voltage B1S1) and heated oxygen sensor (O2 Sensor Voltage B1S2) displayed on the Techstream.

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 is displayed as A/F (O2) Sensor Voltage B1S1, and the heated oxygen sensor is displayed as O2 Sensor Voltage B1S2 on the Techstream.
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
A/F (O2) Sensor Voltage B1S1 (Air fuel ratio)	12.5%	Rich	Below 3.1 V
A/F (O2) Sensor Voltage B1S1 (Air fuel ratio)	-12.5%	Lean	Higher than 3.4 V
O2 Sensor Voltage B1S2 (Heated oxygen)	12.5%	Rich	Higher than 0.55 V
O2 Sensor Voltage B1S2 (Heated oxygen)	-12.5%	Lean	Below 0.4 V

Result

Status A/F (O2) Sensor Voltage B1S1	Status O2 Sensor Voltage B1S2	Actual air fuel ratio, air fuel ratio sensor and heated oxygen sensor condition	Main Suspected Trouble Area	Proceed to
Lean/Rich	Lean/Rich	Normal	Three-way catalytic converter Gas leak from exhaust system EGR valve assembly	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 leak from exhaust system	C
Lean/Rich	Rich	Heated oxygen sensor malfunction	Heated oxygen sensor Gas leak from exhaust system	C
Lean	Lean	Actual air fuel ratio lean	Extremely lean actual air fuel ratio Gas leak from exhaust system EGR valve assembly	D
Rich	Rich	Actual air fuel ratio rich	Extremely rich actual air fuel ratio Gas leak from exhaust system EGR valve assembly	D

Lean: While performing the Active Test "Control the Injection Volume for A/F Sensor", the air fuel ratio sensor output voltage (A/F (O2) Sensor Voltage B1S1) is consistently higher than 3.4 V, and the heated oxygen sensor output voltage (O2 Sensor Voltage B1S2) is consistently below 0.4 V.
Rich: While performing the Active Test "Control the Injection Volume for A/F Sensor", the air fuel ratio sensor output voltage (A/F (O2) Sensor Voltage B1S1) is consistently below 3.1 V, and the heated oxygen sensor output voltage (O2 Sensor Voltage B1S2) is consistently higher than 0.55 V.
Lean/Rich: While performing the Active Test "Control the Injection Volume for A/F Sensor", the output voltage of the fuel ratio sensor (A/F (O2) Sensor Voltage B1S1) or heated oxygen sensor (O2 Sensor Voltage B1S2) alternates correctly.

Result:

See step 6

Result:

See step 7

Result:

See step 9

Result:

See step 3

CHECK FOR EXHAUST GAS LEAK

Check for exhaust gas leaks.

No gas leaks in exhaust system.

Result

Proceed to
OK
NG

Result:

See step 39

Result:

See step 4

PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE EGR STEP POSITION)

Connect the Techstream to the DLC3.
Turn the power switch on (IG).
Turn the Techstream on.

Put the engine in Inspection Mode (Maintenance Mode).

Powertrain > Hybrid Control > Utility

Tester Display
Inspection Mode

Start the engine and warm it up until the engine coolant temperature is 75°C (167°F) or higher.
HINT:

The A/C switch and all accessories should be off.

Enter the following menus: Powertrain / Engine / Active Test / Control the EGR Step Position / Data List / Intake Manifold Absolute Pressure, EGR Step Position and Engine Independent.

Powertrain > Engine > Active Test

Active Test Display
Control the EGR Step Position

Data List Display
Intake Manifold Absolute Pressure
EGR Step Position
Engine Independent

Confirm that the value of Data List item Engine Independent is "Operate" then check the value of Intake Manifold Absolute Pressure while performing the Active Test.

NOTE:

Do not leave the EGR valve open for 10 seconds or more during the Active Test.
Be sure to return the EGR valve to step 0 when the Active Test is completed.
Do not open the EGR valve 30 steps or more during the Active Test.

The value of Intake Manifold Absolute Pressure changes in response to the EGR step position when the value of Engine Independent is "Operate".

Standard

-	Control the EGR Step Position (Active Test)
-	0 Steps	0 to 30 Steps
Intake Manifold Absolute Pressure (Data List)	(EGR valve is fully closed)	Intake Manifold Absolute Pressure value is at least +10 kPa (1.45 psi) higher than when EGR valve is fully closed

HINT:

If the value of Data List item Engine Independent is "Not Opr" when the engine is idling, charge control is being performed. Perform the Active Test after charge control is complete ("Operate" is displayed).
While performing the Active Test, if the increase in the value of Intake Manifold Absolute Pressure is small, the EGR valve assembly may be malfunctioning.
Even if the EGR valve assembly is malfunctioning, rough idling or an increase in the value of Intake Manifold Absolute Pressure may occur while performing the Active Test. However, the amount that the value of Intake Manifold Absolute Pressure increases will be smaller than normal.

Result

Result	Proceed to
The value of Intake Manifold Absolute Pressure increases by 10 kPa(abs) or more, compared to when the EGR valve was fully closed (0 step)	OK
Other than above	NG

HINT:

10 kPa = 1.45 psi

Result:

See step 42

Result:

See step 5

INSPECT EGR VALVE ASSEMBLY

Remove the EGR valve assembly.
HINT:

Refer to REMOVAL [12/2018 - 07/2020]

Check if the EGR valve is stuck open.

EGR valve is tightly closed.

Result

Proceed to
OK
NG

Result:

See step 42

Result:

REPLACE EGR VALVE ASSEMBLY

Refer to REMOVAL [12/2018 - 07/2020]

HINT:

Perform "Inspection After Repair" after replacing the EGR valve assembly.

Refer to INITIALIZATION [11/2015 - ]

REPLACE AIR FUEL RATIO SENSOR

Replace the air fuel ratio sensor.

HINT:

Refer to REMOVAL [11/2015 - ]
Perform "Inspection After Repair" after replacing the air fuel ratio sensor.
Refer to INITIALIZATION [11/2015 - ]

Result

Proceed to
NEXT

Result:

See step 40

CHECK FOR EXHAUST GAS LEAK

Check for exhaust gas leaks.

No gas leaks in exhaust system.

Result

Proceed to
OK
NG

Result:

See step 39

Result:

See step 8

REPLACE HEATED OXYGEN SENSOR

Replace the heated oxygen sensor.

HINT:

Refer to REMOVAL [11/2015 - ]
Perform "Inspection After Repair" after replacing the heated oxygen sensor.
Refer to INITIALIZATION [11/2015 - ]

Result

Proceed to
NEXT

Result:

See step 40

CHECK FOR EXHAUST GAS LEAK

Check for exhaust gas leaks.

No gas leaks in exhaust system.

Result

Proceed to
OK
NG

Result:

See step 39

Result:

See step 10

PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE EGR STEP POSITION)

Connect the Techstream to the DLC3.
Turn the power switch on (IG).
Turn the Techstream on.

Put the engine in Inspection Mode (Maintenance Mode).

Powertrain > Hybrid Control > Utility

Tester Display
Inspection Mode

Start the engine and warm it up until the engine coolant temperature is 75°C (167°F) or higher.
HINT:

The A/C switch and all accessories should be off.

Enter the following menus: Powertrain / Engine / Active Test / Control the EGR Step Position / Data List / Intake Manifold Absolute Pressure, EGR Step Position and Engine Independent.

Powertrain > Engine > Active Test

Active Test Display
Control the EGR Step Position

Data List Display
Intake Manifold Absolute Pressure
EGR Step Position
Engine Independent

Confirm that the value of Data List item Engine Independent is "Operate" then check the value of Intake Manifold Absolute Pressure while performing the Active Test.

NOTE:

Do not leave the EGR valve open for 10 seconds or more during the Active Test.
Be sure to return the EGR valve to step 0 when the Active Test is completed.
Do not open the EGR valve 30 steps or more during the Active Test.

The value of Intake Manifold Absolute Pressure changes in response to the EGR step position when the value of Engine Independent is "Operate".

Standard

-	Control the EGR Step Position (Active Test)
-	0 Steps	0 to 30 Steps
Intake Manifold Absolute Pressure (Data List)	(EGR valve is fully closed)	Intake Manifold Absolute Pressure value is at least +10 kPa (1.45 psi) higher than when EGR valve is fully closed

HINT:

If the value of Data List item Engine Independent is "Not Opr" when the engine is idling, charge control is being performed. Perform the Active Test after charge control is complete ("Operate" is displayed).
While performing the Active Test, if the increase in the value of Intake Manifold Absolute Pressure is small, the EGR valve assembly may be malfunctioning.
Even if the EGR valve assembly is malfunctioning, rough idling or an increase in the value of Intake Manifold Absolute Pressure may occur while performing the Active Test. However, the amount that the value of Intake Manifold Absolute Pressure increases will be smaller than normal.

Result

Result	Proceed to
The value of Intake Manifold Absolute Pressure increases by 10 kPa(abs) or more, compared to when the EGR valve was fully closed (0 step)	OK
Other than above	NG

HINT:

10 kPa = 1.45 psi

Result:

See step 12

Result:

See step 11

INSPECT EGR VALVE ASSEMBLY

Remove the EGR valve assembly.
HINT:

Refer to REMOVAL [12/2018 - 07/2020]

Check if the EGR valve is stuck open.

EGR valve is tightly closed.

Result

Proceed to
OK
NG

Result:

REPLACE EGR VALVE ASSEMBLY

Refer to REMOVAL [12/2018 - 07/2020]

HINT:

Perform "Inspection After Repair" after replacing the EGR valve assembly.

Refer to INITIALIZATION [11/2015 - ]

Result:

See step 12

CHECK PCV HOSE CONNECTIONS

Check the PCV hose connections.

HINT:

Refer to COMPONENTS [11/2015 - ]

PCV valve and hose are connected correctly and are not damaged.

Result

Proceed to
OK
NG

Result:

See step 38

Result:

See step 13

CHECK INTAKE SYSTEM

Check the intake system for vacuum leaks.

Refer to ON-VEHICLE INSPECTION [11/2015 - ]

No leaks from intake system.

Result

Proceed to
OK
NG

Result:

See step 37

Result:

See step 14

PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE INJECTION VOLUME FOR A/F SENSOR)

Connect the Techstream to the DLC3.
Turn the power switch on (IG).
Turn the Techstream on.

Put the engine in Inspection Mode (Maintenance Mode).

Powertrain > Hybrid Control > Utility

Tester Display
Inspection Mode

Start the engine and warm it up until the engine coolant temperature is 75°C (167°F) or higher.
Idle the engine for 5 minutes or more with park (P) selected.

Enter the following menus: Powertrain / Engine / Active Test / Control the Injection Volume for A/F Sensor / Data List / Injection Volume, A/F (O2) Sensor Voltage B1S1 and O2 Sensor Voltage B1S2.

Powertrain > Engine > Active Test

Active Test Display
Control the Injection Volume for A/F Sensor

Data List Display
Injection Volume
A/F (O2) Sensor Voltage B1S1
O2 Sensor Voltage 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 is displayed as A/F (O2) Sensor Voltage B1S1, and the heated oxygen sensor is displayed as O2 Sensor Voltage B1S2 on the Techstream.
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
A/F (O2) Sensor Voltage B1S1 (Air fuel ratio)	12.5%	Rich	Below 3.1 V
A/F (O2) Sensor Voltage B1S1 (Air fuel ratio)	-12.5%	Lean	Higher than 3.4 V
O2 Sensor Voltage B1S2 (Heated oxygen)	12.5%	Rich	Higher than 0.55 V
O2 Sensor Voltage B1S2 (Heated oxygen)	-12.5%	Lean	Below 0.4 V

Result

Status A/F (O2) Sensor Voltage B1S1	Status O2 Sensor Voltage 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 Fuel injector assembly blockage Gas leak from exhaust system Intake system Fuel pressure Mass air flow meter sub-assembly Engine coolant temperature sensor EGR valve assembly
Rich	Rich	Actual air fuel ratio rich	Fuel injector assembly leak or blockage 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 malfunction	Air fuel ratio sensor	B
Rich	Lean/Rich	Air fuel ratio sensor malfunction	Air fuel ratio sensor	B

Lean: While performing the Active Test "Control the Injection Volume for A/F Sensor", the air fuel ratio sensor output voltage (A/F (O2) Sensor Voltage B1S1) is consistently higher than 3.4 V, and the heated oxygen sensor output voltage (O2 Sensor Voltage B1S2) is consistently below 0.4 V.
Rich: While performing the Active Test "Control the Injection Volume for A/F Sensor", the air fuel ratio sensor output voltage (A/F (O2) Sensor Voltage B1S1) is consistently below 3.1 V, and the heated oxygen sensor output voltage (O2 Sensor Voltage B1S2) is consistently higher than 0.55 V.
Lean/Rich: While performing the Active Test "Control the Injection Volume for A/F Sensor", the output voltage of the fuel ratio sensor (A/F (O2) Sensor Voltage B1S1) or heated oxygen sensor (O2 Sensor Voltage B1S2) alternates correctly.

HINT:

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

Refer to DATA LIST / ACTIVE TEST [12/2018 - 08/2019]

Result:

See step 30

Result:

See step 15

READ VALUE USING TECHSTREAM (COOLANT TEMPERATURE)

Connect the Techstream to the DLC3.
Turn the power switch on (IG).
Turn the Techstream on.

Enter the following menus: Powertrain / Engine / Data List / Coolant Temperature.

Powertrain > Engine > Data List

Tester Display
Coolant Temperature

Read the Data List twice, when the engine is both cold and warmed up.

Standard

Techstream Display	Condition	Specified Condition
Coolant Temperature	Cold engine	Same as ambient air temperature
Coolant Temperature	Warm engine	Between 75 and 100°C (167 and 212°F)

Result

Proceed to
OK
NG

Result:

See step 29

Result:

See step 16

PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE EGR STEP POSITION)

Connect the Techstream to the DLC3.
Turn the power switch on (IG).
Turn the Techstream on.

Put the engine in Inspection Mode (Maintenance Mode).

Powertrain > Hybrid Control > Utility

Tester Display
Inspection Mode

Start the engine and warm it up until the engine coolant temperature is 75°C (167°F) or higher.
HINT:

The A/C switch and all accessories should be off.

Enter the following menus: Powertrain / Engine / Active Test / Control the EGR Step Position / Data List / Intake Manifold Absolute Pressure, EGR Step Position and Engine Independent.

Powertrain > Engine > Active Test

Active Test Display
Control the EGR Step Position

Data List Display
Intake Manifold Absolute Pressure
EGR Step Position
Engine Independent

Confirm that the value of Data List item Engine Independent is "Operate" then check the value of Intake Manifold Absolute Pressure while performing the Active Test.

NOTE:

Do not leave the EGR valve open for 10 seconds or more during the Active Test.
Be sure to return the EGR valve to step 0 when the Active Test is completed.
Do not open the EGR valve 30 steps or more during the Active Test.

The value of Intake Manifold Absolute Pressure changes in response to the EGR step position when the value of Engine Independent is "Operate".

Standard

-	Control the EGR Step Position (Active Test)
-	0 Steps	0 to 30 Steps
Intake Manifold Absolute Pressure (Data List)	(EGR valve is fully closed)	Intake Manifold Absolute Pressure value is at least +10 kPa (1.45 psi) higher than when EGR valve is fully closed

HINT:

If the value of Data List item Engine Independent is "Not Opr" when the engine is idling, charge control is being performed. Perform the Active Test after charge control is complete ("Operate" is displayed).
While performing the Active Test, if the increase in the value of Intake Manifold Absolute Pressure is small, the EGR valve assembly may be malfunctioning.
Even if the EGR valve assembly is malfunctioning, rough idling or an increase in the value of Intake Manifold Absolute Pressure may occur while performing the Active Test. However, the amount that the value of Intake Manifold Absolute Pressure increases will be smaller than normal.

Result

Result	Proceed to
The value of Intake Manifold Absolute Pressure increases by 10 kPa(abs) or more, compared to when the EGR valve was fully closed (0 step)	OK
Other than above	NG

HINT:

10 kPa = 1.45 psi

Result:

See step 18

Result:

See step 17

INSPECT EGR VALVE ASSEMBLY

Remove the EGR valve assembly.
HINT:

Refer to REMOVAL [12/2018 - 07/2020]

Check if the EGR valve is stuck open.

EGR valve is tightly closed.

Result

Proceed to
OK
NG

Result:

See step 28

Result:

See step 18

READ VALUE USING TECHSTREAM (MASS AIR FLOW SENSOR)

Connect the Techstream to the DLC3.
Turn the power switch on (IG).
Turn the Techstream on.

Put the engine in Inspection Mode (Maintenance Mode).

Powertrain > Hybrid Control > Utility

Tester Display
Inspection Mode

Start the engine.

Enter the following menus: Powertrain / Engine / Data List / Engine Speed, Mass Air Flow Sensor and Coolant Temperature.

Powertrain > Engine > Data List

Tester Display
Engine Speed
Mass Air Flow Sensor
Coolant Temperature

Allow the engine to idle until Coolant Temperature is 75°C (167°F) or higher.

Read Mass Air Flow Sensor with the engine speed at 2500 rpm.

HINT:

During charge control, the engine speed is set at idle. Therefore, the engine speed will not increase when the accelerator pedal is depressed. In this case, read the Data List after charge control has completed.

Standard

Techstream Display	Condition	Specified Condition
Mass Air Flow Sensor	Engine warmed up Shift position: P A/C: Off Engine Speed: 2500 rpm	Between 4.5 and 8.5 gm/sec

Result

Result	Proceed to
The value of Mass Air Flow Sensor is between 4.5 gm/sec and 8.5 gm/sec	OK
Other than above	NG

Result:

See step 23

Result:

See step 19

CHECK FUEL PRESSURE

Check the fuel pressure.

Refer to ON-VEHICLE INSPECTION [12/2018 - ]

Result

Proceed to
OK
NG

Result:

See step 27

Result:

See step 20

CHECK FOR EXHAUST GAS LEAK

Check for exhaust gas leaks.

No gas leaks in exhaust system.

Result

Proceed to
OK
NG

Result:

See step 26

Result:

See step 21

INSPECT IGNITION SYSTEM

Inspect the ignition system.

Refer to ON-VEHICLE INSPECTION [11/2015 - ]

HINT:

If the spark plugs or ignition system malfunctions, engine misfire may occur. The misfire count can be read using the Techstream. Enter the following menus: Powertrain / Engine / Data List / Misfire Count Cylinder #1 to Misfire Count Cylinder #4.

Result

Proceed to
OK
NG

Result:

See step 25

Result:

See step 22

INSPECT FUEL INJECTOR ASSEMBLY (INJECTION AND VOLUME)

Check the injection and volume.

HINT:

Refer to the fuel injector assembly inspection procedure.
Refer to INSPECTION [12/2018 - ]
If the fuel injector assemblies malfunction, engine misfire may occur. The misfire count can be read using the Techstream. Enter the following menus: Powertrain / Engine / Data List / Misfire Count Cylinder #1 to Misfire Count Cylinder #4.

Result

Proceed to
OK
NG

Result:

See step 24

Result:

See step 23

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

Check the connection and terminal contact pressure of connectors and wire harnesses between the mass air flow meter sub-assembly and ECM.

HINT:

Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE [11/2015 - ]
Repair any problems.

Result

Proceed to
NEXT

Result:

See step 40

REPLACE FUEL INJECTOR ASSEMBLY

Replace the fuel injector assembly.

HINT:

Refer to REMOVAL [12/2018 - 07/2020]
Perform "Inspection After Repair" after replacing the fuel injector assembly.
Refer to INITIALIZATION [11/2015 - ]

Result

Proceed to
NEXT

Result:

See step 40

REPAIR OR REPLACE IGNITION SYSTEM

Repair or replace the ignition system.

HINT:

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

Refer to INITIALIZATION [11/2015 - ]

Result

Proceed to
NEXT

Result:

See step 40

REPAIR OR REPLACE EXHAUST SYSTEM

Repair or replace the exhaust system.

HINT:

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

Refer to INITIALIZATION [11/2015 - ]

Result

Proceed to
NEXT

Result:

See step 40

REPAIR OR REPLACE FUEL SYSTEM

Repair or replace the fuel system.

Result

Proceed to
NEXT

Result:

See step 40

REPLACE EGR VALVE ASSEMBLY

Replace the EGR valve assembly.

HINT:

Refer to REMOVAL [12/2018 - 07/2020]
Perform "Inspection After Repair" after replacing the EGR valve assembly.
Refer to INITIALIZATION [11/2015 - ]

Result

Proceed to
NEXT

Result:

See step 40

REPLACE ENGINE COOLANT TEMPERATURE SENSOR

Replace the engine coolant temperature sensor.

HINT:

Refer to REMOVAL [11/2015 - ]
Perform "Inspection After Repair" after replacing the engine coolant temperature sensor.
Refer to INITIALIZATION [11/2015 - ]

Result

Proceed to
NEXT

Result:

See step 40

INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE)

Inspect the air fuel ratio sensor.

Refer to INSPECTION [11/2015 - ]

Result

Proceed to
OK
NG

Result:

See step 36

Result:

See step 31

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

Disconnect the air fuel ratio sensor connector.
Turn the power switch on (IG).

Measure the voltage according to the value(s) in the table below.

Standard Voltage

(C24)

Tester Connection	Condition	Specified Condition
C24-2 (+B) - Body ground	Power switch on (IG)	11 to 14 V

Result

Proceed to
OK
NG

Result:

See step 35

Result:

See step 32

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

Disconnect the air fuel ratio sensor connector.
Disconnect the ECM connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance

(C24, C31)

(C24)

(C31)

Tester Connection	Condition	Specified Condition
C24-1 (HA1A) - C31-27 (HA1A)	Always	Below 1 Ω
C24-3 (A1A+) - C31-100 (A1A+)	Always	Below 1 Ω
C24-4 (A1A-) - C31-132 (A1A-)	Always	Below 1 Ω
C24-1 (HA1A) or C31-27 (HA1A) - Body ground and other terminals	Always	10 kΩ or higher
C24-3 (A1A+) or C31-100 (A1A+) - Body ground and other terminals	Always	10 kΩ or higher
C24-4 (A1A-) or C31-132 (A1A-) - Body ground and other terminals	Always	10 kΩ or higher

Result

Proceed to
OK
NG

Result:

See step 34

Result:

See step 33

REPLACE AIR FUEL RATIO SENSOR

Replace the air fuel ratio sensor.

HINT:

Refer to REMOVAL [11/2015 - ]
Perform "Inspection After Repair" after replacing the air fuel ratio sensor.
Refer to INITIALIZATION [11/2015 - ]

Result

Proceed to
NEXT

Result:

See step 40

REPAIR OR REPLACE HARNESS OR CONNECTOR

Repair or replace the wire harness or connector.

Result

Proceed to
NEXT

Result:

See step 40

REPAIR OR REPLACE HARNESS OR CONNECTOR (NO. 1 INTEGRATION RELAY - AIR FUEL RATIO SENSOR)

Repair or replace the wire harness or connector.

Result

Proceed to
NEXT

Result:

See step 40

REPLACE AIR FUEL RATIO SENSOR

Replace the air fuel ratio sensor.

HINT:

Refer to REMOVAL [11/2015 - ]
Perform "Inspection After Repair" after replacing the air fuel ratio sensor.
Refer to INITIALIZATION [11/2015 - ]

Result

Proceed to
NEXT

Result:

See step 40

REPAIR OR REPLACE INTAKE SYSTEM

Repair or replace the intake system.

HINT:

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

Refer to INITIALIZATION [11/2015 - ]

Result

Proceed to
NEXT

Result:

See step 40

REPAIR OR REPLACE PCV HOSE

Repair or replace the PCV hose.

Result

Proceed to
NEXT

Result:

See step 40

REPAIR OR REPLACE EXHAUST SYSTEM

Repair or replace exhaust system.

HINT:

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

Refer to INITIALIZATION [11/2015 - ]

Result

Proceed to
NEXT

Result:

See step 40

CLEAR DTC

Connect the Techstream to the DLC3.
Turn the power switch on (IG).
Turn the Techstream on.
Clear the DTCs.
Powertrain > Engine > Clear DTCs

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

Result

Proceed to
NEXT

Result:

See step 41

CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
Enter the following menus: Powertrain / Engine / Trouble Codes.

Read the DTCs.

Powertrain > Engine > Trouble Codes

Result

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

Result:

END

Result:

See step 42

REPLACE EXHAUST MANIFOLD (TWC: FRONT CATALYST) AND FRONT EXHAUST PIPE ASSEMBLY (TWC: REAR CATALYST)

NOTE:

When replacing the exhaust manifold and the front exhaust pipe assembly in order to replace the three-way catalytic converter, it is not necessary to replace the air fuel ratio sensor and the heated oxygen sensor.

HINT:

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

Replace the exhaust manifold (TWC: Front catalyst).
HINT:

Refer to COMPONENTS [12/2018 - 08/2019]

Replace the front exhaust pipe assembly (TWC: Rear catalyst).

HINT:

Refer to COMPONENTS [12/2018 - 08/2019]

Result

Proceed to
NEXT

Result:

END