Diagnosis Procedure

Visually check exhaust tubes, three way catalyst and muffler for dent.

Is the inspection result normal?

YES

GO TO 2.

NO

Repair or replace error-detected parts. Refer to Exploded View .

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

   Courtesy of NISSAN NORTH AMERICA, INC.

   	Three way catalyst		A/F sensor 1		HO2S2
   	Muffler

Is the inspection result normal?

YES

GO TO 3.

NO

Repair or replace error-detected parts. Refer to Exploded View .

1. Start engine and let it idle.
2. Listen for an intake air leak after the mass air flow sensor.

Is the inspection result normal?

YES

GO TO 4.

NO

Repair or replace error-detected parts. Refer to Exploded View .

Check the following items.

For specification, refer to Ignition Timing

For specification, refer to Idle Speed .

Is the inspection result normal?

YES

GO TO 5.

NO

Follow the Exploded View .

Check the direct fuel injector. Refer to Diagnosis Procedure .

Is the inspection result normal?

YES

GO TO 6.

NO

Perform Diagnosis Procedure .

Check the port fuel injector. Refer to Diagnosis Procedure .

Is the inspection result normal?

YES

GO TO 7.

NO

Perform Diagnosis Procedure .

1. Turn ignition switch OFF.
2. Remove fuel pump fuse in IPDM E/R to release fuel pressure.
   NOTE: Do not use CONSULT to release fuel pressure, or fuel pressure applies again during the following procedure.
3. Start engine.
4. After engine stalls, crank it two or three times to release all fuel pressure
5. Turn ignition switch OFF.
6. Remove all ignition coil harness connectors to avoid the electrical discharge from the ignition coils.
7. Remove ignition coil and spark plug of the cylinder to be checked. Refer to Exploded View .
8. Crank engine for 5 seconds or more to remove combustion gas in the cylinder.
9. Connect spark plug and harness connector to ignition coil.
10. Fix ignition coil using a rope etc. with gap of 13 - 17 mm (0.52 - 0.66 in) between the edge of the spark plug and grounded metal portion as shown in the figure.

    Courtesy of NISSAN NORTH AMERICA, INC.

11. Crank engine for about 3 seconds, and check whether spark is generated between the spark plug and the grounded metal portion.
    CAUTION:

    • Do not approach to the spark plug and the ignition coil within 50 cm (19.7 in). Be careful not to get an electrical shock while checking, because the electrical discharge voltage becomes 20 kV or more.
    • It might cause to damage the ignition coil if the gap of more than 17 mm (0.66 in) is taken.
    NOTE: When the gap is less than 13 mm (0.52 in), the spark might be generated even if the coil is malfunctioning.

Is the inspection result normal?

YES

GO TO 11.

NO

GO TO 8.

1. Turn ignition switch OFF.
2. Disconnect spark plug and connect a known-good spark plug.
3. Crank engine for about 3 seconds, and recheck whether spark is generated between the spark plug and the grounded metal portion.

   Spark should be generated.

Is the inspection result normal?

YES

GO TO 9.

NO

Check ignition coil, power transistor and their circuits. Refer to Diagnosis Procedure .

Check the initial spark plug for fouling, etc.

Courtesy of NISSAN NORTH AMERICA, INC.

Is the inspection result normal?

YES

Replace spark plug(s) with standard type one(s). For spark plug type, refer to Spark Plug .

NO

Repair or clean spark plug. Refer to Exploded View . Then GO TO 10.

1. Reconnect the initial spark plugs.
2. Crank engine for about 3 seconds, and recheck whether spark is generated between the spark plug and the grounded portion.

   Spark should be generated.

Is the inspection result normal?

YES

INSPECTION END

NO

Replace spark plug(s) with standard type one(s). For spark plug type, refer to Spark Plug .

1. Replace three way catalyst (manifold). Refer to Removal and Installation .
2. Perform DTC confirmation procedure. Refer to DTC Description .

Is DTC P0420 detected again?

YES

Replace all fuel injector. Refer to Removal and Installation and Removal and Installation .

NO

INSPECTION END