Diagnostic Procedure

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

OK or NG

1. OK: Go to 2.
2. NG: Repair or replace.

Listen for an intake air leak after the mass air flow sensor.

OK or NG

1. OK: Go to 3.
2. NG: Repair or replace.

1. Turn ignition switch OFF.
2. Disconnect corresponding air fuel ratio (A/F) sensor 1 harness connector. See Figure.
3. Disconnect ECM harness connector.
4. Check harness continuity between the following terminals. See Figure.

   Refer to wiring diagram WIRING DIAGRAM .

   Continuity should exist  .

5. Check harness continuity between the following terminals and ground. See Figure.

   Refer to wiring diagram. See WIRING DIAGRAM .

   Continuity should not exist  .

6. Also check harness for short to ground and short to power.

OK or NG

1. OK: Go to 4.
2. NG: Repair open circuit or short to ground or short to power in harness or connectors.

1. Release fuel pressure to zero. Refer to FUEL PRESSURE RELEASE .
2. Install fuel pressure gauge and check fuel pressure. Refer to FUEL PRESSURE CHECK .

At idling: 350 kPa (3.57 kg/cm2, 51 psi) 

OK or NG

1. OK: Go to 6.
2. NG: Go to 5.

Check the following.

• Fuel pump and circuit. Refer to FUEL PUMP CIRCUIT .
• Fuel pressure regulator. Refer to FUEL PRESSURE CHECK .

1. Repair or replace.

With CONSULT-II 

1. Install all removed parts.
2. Check MASS AIR FLOW in DATA MONITOR mode with CONSULT-II.

   2.0 - 6.0 g.m/sec: at idling 

   7.0 - 20.0 g.m/sec: at 2,500 RPM 

With GST 

1. Install all removed parts.
2. Check mass air flow sensor signal in MODE 1 with GST.

   2.0 - 6.0 g.m/sec: at idling 

   7.0 - 20.0 g.m/sec: at 2,500 RPM 

OK or NG

1. OK: Go to 7.
2. NG: Check connectors for rusted terminals or loose connections in the mass air flow sensor circuit or engine grounds. Refer to DTC P0101 MAF SENSOR .

With CONSULT-II 

1. Start engine.
2. Perform POWER BALANCE in ACTIVE TEST mode with CONSULT-II. See Figure.
3. Make sure that each circuit produces a momentary engine speed drop.

Without CONSULT-II 

1. Start engine.
2. Listen to each injector operating sound.

Clicking noise should be heard  .

OK or NG

1. OK: Go to 8.
2. NG: Perform trouble diagnosis for INJECTORS, INJECTOR CIRCUIT .

1. Remove injector assembly. Refer to FUEL INJECTOR AND FUEL TUBE .

   Keep fuel hose and all injectors connected to injector gallery.

2. Confirm that the engine is cooled down and there are no fire hazards near the vehicle.
3. Disconnect all injector harness connectors.
4. Disconnect all ignition coil harness connectors.
5. Prepare pans or saucers under each injectors.
6. Crank engine for about 3 seconds.

   Make sure fuel does not drip from injector.

OK or NG

1. OK (Does not drip.): Go to 9.
2. NG (Drips.): Replace the injectors from which fuel is dripping. Always replace "O" ring with new one.

Refer to TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT .

1. Inspection end