1.CHECK GROUND CONNECTION
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 EM, "Exploded View".
>> GO TO 3.
3.CHECK EXHAUST GAS LEAK
Is exhaust gas leak detected?
YES >> Repair or replace.
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.
NO >> GO TO 5.
5.CLEAR THE MIXTURE RATIO SELFLEARNING VALUE
Is the 1st trip DTC P0171 or P172 detected? Is it difficult to start engine?
YES >> Perform trouble diagnosis for DTC P0171 or P0172. Refer to EC, "DTC Logic" or EC, "DTC Logic".
NO >> GO TO 6.
6.CHECK AIR FUEL RATIO (A/F) SENSOR 1 POWER SUPPLY CIRCUIT
Is the inspection result normal?
YES >> GO TO 8.
NO >> GO TO 7.
7.DETECT MALFUNCTIONING PART
Check the following.
>> Repair or replace harness or connectors.
8.CHECK A/F SENSOR 1 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
4. Check the continuity between A/F sensor 1 harness connector and ground, or ECM harness connector and ground.
5. Also check harness for short to power.
Is the inspection result normal?
YES >> GO TO 9.
NO >> Repair open circuit or short to ground or short to power in harness or connectors.
9.CHECK AIR FUEL RATIO (A/F) SENSOR 1 HEATER
Refer to EC, "Component Inspection".
Is the inspection result normal?
YES >> GO TO 10.
NO >> GO TO 13.
10.CHECK MASS AIR FLOW SENSOR
Refer to EC, "Component Inspection".
Is the inspection result normal?
YES >> GO TO 11.
NO >> Replace mass air flow sensor. Refer to EM, "Removal and Installation".
11.CHECK PCV VALVE
Refer to EC, "Inspection".
Is the inspection result normal?
YES >> GO TO 12.
NO >> Repair or replace PCV valve. Refer to EM, "Exploded View".
12.CHECK INTERMITTENT INCIDENT
Perform GI, "Intermittent Incident".
Is the inspection result normal?
YES >> GO TO 13.
NO >> Repair or replace.
13.REPLACE AIR FUEL RATIO (A/F) SENSOR 1
Replace air fuel ratio (A/F) sensor 1. Refer to EM, "Exploded View".
CAUTION:
>> INSPECTION END