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Inspection procedure 16: Too high CO and HC concentration when idling
 
 
 
 
COMMENT
  • Abnormal air/fuel ratio is suspected.
 
 
TROUBLESHOOTING HINTS (The most likely causes for this case: )
  • Use of incorrect engine oil level or viscosity
  • Contaminated fuel.
  • Fuel pump system failed.
  • Evaporative emission control system failed.
  • Improper operation of the PCV valve.
  • Linear air-fuel ratio sensor failed.
  • Heated oxygen sensor (rear) failed.
  • Ignition system failed.
  • Poor compression.
  • Vacuum leak.
  • Intake charge pressure control system failed.
  • Catalytic converter deteriorated.
  • ECM failed.

 
 
DIAGNOSIS
STEP 1. Using scan tool (M.U.T.-IIISE), read the diagnostic trouble code (DTC).
cautionTo prevent damage to scan tool (M.U.T.-IIISE), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T.-IIISE).
(1) Connect scan tool (M.U.T.-IIISE). Refer to HOW TO CONNECT THE SCAN TOOL (M.U.T.-IIISE) .
(2) Turn the ignition switch to the "ON" position.
(3) Read the DTC.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Is any DTC set?
Refer to Diagnostic Trouble Code Chart .
Go to Step 2.
 
STEP 2. Check the engine oil.
Refer to GROUP 12, On-vehicle Service - Engine Oil Check .
note
  • The overfilling of engine oil, or oil dilution due to an injector malfunction or short distance travelling in the cold condition may cause the oil level to be high.
  • Oil rise, oil fall, or increase of oil consumption due to the malfunction of the positive crankcase ventilation system may cause the oil level to be low.
Is the engine oil normal?
Go to Step 3.
Repair or replace it. Then confirm that the malfunction symptom is eliminated.
 
STEP 3. Check the positive crankcase ventilation system.
Refer to GROUP 17, Emission Control - Positive Crankcase Ventilation System - Crankcase Ventilation System Check .
Is the positive crankcase ventilation system normal?
Go to Step 4.
Repair it. Then confirm that the malfunction symptom is eliminated.
 
STEP 4. Check for entry of foreign matter (water, kerosene, etc.) into fuel.
Are there any abnormalities?
Replace the fuel. Then confirm that the malfunction symptom is eliminated.
Go to Step 5.
 
STEP 5. Check the idle speed.
Refer to GROUP 11A, On-vehicle Service - Curb Idle Speed Check .
Is the idle speed normal?
Go to Step 6.
Refer to Inspection Procedure - Idle Speed Is High (improper idle speed) , Inspection Procedure - Idle Speed is Low (improper idle speed) .
 
STEP 6. Using scan tool (M.U.T.-IIISE), check actuator test.
(1) Turn the ignition switch to the "ON" position.
(2) Check the following item in the actuator test. Refer to Actuator Test Reference Table .
  1. Item 1: Injector Stop
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Are they operating properly?
Go to Step 7.
Refer to, DTC P0261 - Injector Circuit Low input - Cylinder 1 , DTC P0262 - Injector Circuit High input - Cylinder 1 , DTC P0264 - Injector Circuit Low Input - Cylinder 2 , DTC P0265 - Injector Circuit High input - Cylinder 2 , DTC P0267 - Injector Circuit Low Input - Cylinder 3 , DTC P0268 - Injector Circuit High input - Cylinder 3 , DTC P0270 - Injector Circuit Low Input - Cylinder 4 , DTC P0271 - Injector Circuit High input - Cylinder 4 .
 
STEP 7. Check the ignition timing.
Refer to GROUP 11A, On-vehicle Service - Ignition Timing Check .
Is the ignition timing normal?
Go to Step 8.
Check for installed conditions of the timing chain. Then confirm that the malfunction symptom is eliminated.
 
STEP 8. Visual check of ignition spark.
(1) Remove the spark plug and install it to the ignition coil.
(2) Connect the ignition coil connector.
(3) Remove all injector connector.
(4) At the engine start, check each spark plug produces a spark.
Did it spark?
Go to Step 9.
Refer to Symptom Procedures - Ignition Circuit System .
 
STEP 9. Using scan tool (M.U.T.-IIISE), check data list.
(1) Turn the ignition switch to the "ON" position.
(2) Check the following items in the data list. Refer to Data List Reference Table .
  1. Item 5: Intake Air Temperature Sensor 1
  2. Item 6: Engine Coolant Temperature Sensor
  3. Item 10: Mass Airflow Sensor
  4. Item 36: Intake MIVEC Phase Angle
  5. Item 39: Exhaust MIVEC Phase Angle
  6. Item 46: Turbocharger Wastegate Actuator Duty
  7. Item DE: Intake Air Temperature Sensor 2
  8. Item 125: Boost Pressure Sensor
  9. Item 126: Manifold Absolute Pressure Sensor
  10. Item 127: Turbocharger Wastegate Position Sensor
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Are they operating properly?
Go to Step 10.
Repair or replace it. Then confirm that the malfunction symptom is eliminated.
 
STEP 10. Check for intake system vacuum leak.
Are there any abnormalities?
Repair it. Then confirm that the malfunction symptom is eliminated.
Go to Step 11.
 
STEP 11. Check for exhaust leak.
Are there any abnormalities?
Repair it. Then confirm that the malfunction symptom is eliminated.
Go to Step 12.
 
STEP 12. Inspection of throttle body (throttle valve area) for dirtiness.
Is the throttle valve area dirty?
Refer to Throttle Body (throttle valve area) Cleaning .
Go to Step 13.
 
STEP 13. Using scan tool (M.U.T.-IIISE), check data list.
(1) Turn the ignition switch to the "ON" position.
(2) Check the following items in the data list. Refer to Data List Reference Table .
  1. Item AD: Heated Oxygen Sensor (rear)
  2. Item E1: Linear Air-fuel Ratio Sensor
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Are they operating properly?
Go to Step 14.
Repair or replace it. Then confirm that the malfunction symptom is eliminated.
 
STEP 14. Check the purge control system.
Refer to GROUP 17, Emission Control - Evaporative Emission Control System - Purge Control System Check (Purge Flow Check) .
Is the purge control system normal?
Go to Step 15.
Repair it. Then confirm that the malfunction symptom is eliminated.
 
STEP 15. Check the compression pressure.
Refer to GROUP 11A, On-vehicle Service - Compression Pressure Check .
Is the compression pressure normal?
Go to Step 16.
Repair it. Then confirm that the malfunction symptom is eliminated.
 
STEP 16. Check the fuel pressure.
Refer to Fuel Pressure Test .
Is the fuel pressure normal?
Go to Step 17.
Repair it. Then confirm that the malfunction symptom is eliminated.
 
STEP 17. Check the intake charge pressure.
Refer to GROUP 15, On-vehicle Service - Intake Charge Pressure Check .
Is the intake charge pressure normal?
Go to Step 18.
Repair it. Then confirm that the malfunction symptom is eliminated.
 
STEP 18. Replace the exhaust front pipe (integrated with catalytic converter).
(1) Replace the exhaust front pipe (integrated with catalytic converter).
(2) Confirm that the malfunction symptom is eliminated.
Does the malfunction symptom persist?
Go to Step 19.
The inspection is complete.
 
STEP 19. Replace the injector (high pressure).
(1) Replace the injector (high pressure).
(2) Confirm that the malfunction symptom is eliminated.
Does the malfunction symptom persist?
Replace the ECM (Refer to Removal and Installation ). Then confirm that the malfunction symptom is eliminated.
The inspection is complete.