1.CHECK GROUND CONNECTION

1. Turn ignition switch OFF.
2. Check ground connection M95. Refer to Ground Inspection in Circuit Inspection.

Is the inspection result normal?
YES>>GO TO 2.
NO>>Repair or replace ground connection.
2.RETIGHTEN A/F SENSOR 1
Loosen and retighten the A/F sensor 1. Refer to Disassembly and Assembly (GT-R certified NISSAN dealer).
>>GO TO 3.
3.CHECK EXHAUST GAS LEAK

1. Start engine and run it at idle.
2. Listen for an exhaust gas leak before three way catalyst 1.

Is exhaust gas leak detected?
YES>>Repair or replace malfunctioning part.
NO>>GO TO 4.
4.CHECK FOR INTAKE AIR LEAK
Listen for an intake air leak after the mass air flow sensor.
Is intake air leak detected?
YES>>Repair or replace malfunctioning part.
NO>>GO TO 5.
5.CLEAR THE MIXTURE RATIO SELF-LEARNING VALUE

1. Clear the mixture ratio self-learning value. Refer to Special Repair Requirement (GT-R certified NISSAN dealer).
2. Run engine for at least 10 minutes at idle speed.

Is the 1st trip DTC P0171, P172, P0174 or P0175 detected? Is it difficult to start engine?
YES>>Perform trouble diagnosis for DTC P0171, P0174 or P0172, P0175. Refer to DTC Logic (GT-R certified NISSAN dealer) or DTC Logic (GT-R certified NISSAN dealer).
NO>>GO TO 6.
6.CHECK AIR FUEL RATIO (A/F) SENSOR 1 POWER SUPPLY CIRCUIT

1. Disconnect A/F sensor 1 harness connector.
2. Turn ignition switch ON.
3. Check the voltage between A/F sensor 1 harness connector and ground.

   DTC | A/F sensor 1 | Ground | Voltage
   Bank | Connector | Terminal
   P0133 | 1 | F8 | 4 | Ground | Battery voltage
   P0153 | 2 | F25 | 4

Is the inspection result normal?
YES>>GO TO 8.
NO>>GO TO 7.
7.DETECT MALFUNCTIONING PART
Check the following.

- Harness connectors E3, F1
- IPDM E/R harness connector E7
- 15A fuse (No. 46)
- Harness for open or short between A/F sensor 1 and fuse

>>Repair or replace harness or connectors.
8.CHECK A/F SENSOR 1 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between A/F sensor 1 harness connector and ECM harness connector.

   DTC | A/F sensor 1 | ECM | Continuity
   Bank | Connector | Terminal | Connector | Terminal
   P0133 | 1 | F8 | 1 | F102 | 81 | Existed
   2 | 82
   P0153 | 2 | F25 | 1 | 85
   2 | 86

4. Check the continuity between A/F sensor 1 harness connector or ECM harness connector and ground.

   DTC | A/F sensor 1 | ECM | Ground | Continuity
   Bank | Connector | Terminal | Connector | Terminal
   P0133 | 1 | F8 | 1 | F102 | 81 | Ground | Not existed
   2 | 82
   P0153 | 2 | F25 | 1 | 85
   2 | 86

5. Also check harness for short to power.

Is the inspection result normal?
YES>>GO TO 9.
NO>>Repair open circuit, short to ground or short to power in harness or connectors.
9.CHECK AIR FUEL RATIO (A/F) SENSOR 1 HEATER
Refer to Component Inspection (GT-R certified NISSAN dealer).
Is the inspection result normal?
YES>>GO TO 10.
NO>>GO TO 13.
10.CHECK MASS AIR FLOW SENSOR
Check both mass air flow sensor (bank 1 and bank 2).
Refer to Component Inspection (GT-R certified NISSAN dealer).
Is the inspection result normal?
YES>>GO TO 11.
NO>>Replace malfunctioning mass air flow sensor.
11.CHECK PCV VALVE
Refer to Component Inspection.
Is the inspection result normal?
YES>>GO TO 12.
NO>>Repair or replace PCV valve.
12.CHECK INTERMITTENT INCIDENT
Perform Intermittent Incident.
Is the inspection result normal?
YES>>GO TO 13.
NO>>Repair or replace malfunctioning part.
13.REPLACE AIR FUEL RATIO (A/F) SENSOR 1
Replace malfunctioning air fuel ratio (A/F) sensor 1.
■ CAUTION ■

- Discard any A/F sensor which has been dropped from a height of more than 0.5 m (1.6 ft) onto a hard surface such as a concrete floor; use a new one.
- Before installing new A/F sensor, clean exhaust system threads using Oxygen Sensor Thread Cleaner [commercial service tool (J-43897-18 or J-43897-12)] and approved anti-seize lubricant (commercial service tool).

>>INSPECTION END