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Inspection Procedure 8: Transient, mass emission tailpipe test failure
 
 
 
 
COMMENT
The test is failed when the air-fuel ratio is not controlled to the ideal air-fuel ratio. This occurs due to the feedback control by heated oxygen sensor signals, insufficient EGR flow rate or deteriorated catalyst.
noteIf the three-way catalyst temperature is low when checking the exhaust gas, the three-way catalyst cannot sufficiently clean the emissions. Warm up the engine sufficiently before checking the exhaust, and check immediately.
 
 
TROUBLESHOOTING HINTS (The most likely causes for this case:)
  • Air-fuel ratio control system failed.
  • Fuel pump system failed.
  • Ignition system failed.
  • Poor compression.
  • EGR system failed.
  • Improper operation of the PCV valve.
  • Evaporative emission system failed.
  • Deteriorated catalyst.
 
 
DIAGNOSIS
Required Special Tools:
  • MB992744: Vehicle communication interface-Lite (V.C.I.-Lite)
  • MB992745: V.C.I.-Lite main harness A
  • MB992747: V.C.I.-Lite USB cable short
  • MB992748: V.C.I.-Lite USB cable long
1.STEP 1. Check the EGR valve (stepper motor).
Check the EGR valve operation sound [Refer to ENGINE, Engine, Motor and Emission Control – Emission Control – Exhaust Gas Recirculation (EGR) System EXHAUST GAS RECIRCULATION (EGR) VALVE (STEPPER MOTOR) CHECK].
Q: Is the check result normal?
Check the EGR valve itself [Refer to ENGINE, Engine, Motor and Emission Control – Emission Control – Exhaust Gas Recirculation (EGR) System EXHAUST GAS RECIRCULATION (EGR) VALVE (STEPPER MOTOR) CHECK].
 
2.STEP 2. Check the exhaust gas with the engine at normal operating temperature.
Q: Was the exhaust gas checked with engine warmed sufficiently?
Check it again after enough warm up.
 
3.STEP 3. Check the following items.
Check the following items.
  • Check all vacuum hoses and connectors.
  • Check electrical wires and connectors for obvious problems.
Q: Are the check result normal?
Repair or replace it.
 
4.STEP 4. Check the driveability.
Q: Is the driveability normal?
Refer to Symptom Chart SYMPTOM CHART.
 
5.STEP 5. Using scan tool (M.U.T.-III SE), read the DTC.
Use scan tool (M.U.T.-III SE) to check and see if a DTC is set in the ECM (Refer to HOW TO READ AND ERASE DIAGNOSTIC TROUBLE CODES).
Q: Is any DTC set?
Perform troubleshooting for the set DTC (Refer to DIAGNOSTIC TROUBLE CODE CHART).
 
6.STEP 6. Check the ignition timing.
Check the ignition timing (Refer to ENGINE, Engine Mechanical – On-vehicle Service IGNITION TIMING CHECK ).
Q: Is the ignition timing normal?
Align the timing marks (Refer to ENGINE, Engine Overhaul – Timing Chain TIMING CHAIN REMOVAL AND INSTALLATION ).
 
7.STEP 7. Using scan tool (M.U.T.-III SE), check the data list.
Use scan tool (M.U.T.-III SE) to check the data list (Refer to DATA LIST REFERENCE TABLE).
  • Item number 50: Air Temperature Sensor
  • Item number 60: Coolant (Water) Temperature Sensor
  • Item number A3301: Barometric pressure sensor
Q: Are the check result normal?
Perform the DTC classified check procedure for the sensor that has shown an abnormal data value (Refer to DIAGNOSTIC TROUBLE CODE CHART).
 
8.STEP 8. Using scan tool (M.U.T.-III SE), check the data list.
Use scan tool (M.U.T.-III SE) to check the data list (Refer to DATA LIST REFERENCE TABLE).
  • Item number A1501: Oxygen sensor(bank1 sensor2)
Q: Is the check result normal?
Perform troubleshooting for the heated oxygen sensor (rear) circuit [Refer to DTC P0137-00: Oxygen Sensor (rear) circuit low voltage DTC P0137-00: Oxygen Sensor (rear) circuit low voltage), Refer to DTC P0138-00: Oxygen Sensor (rear) circuit high voltage DTC P0138-00: Oxygen Sensor (rear) circuit high voltage), Refer to DTC P0139-00: Heated oxygen sensor (rear) slow response DTC P0139-00: Heated oxygen sensor (rear) slow response), and Refer to DTC P0140-00: Heated oxygen sensor (rear) no activity detected DTC P0140-00: Heated oxygen sensor (rear) no activity detected)].
 
9.STEP 9. Check for air intake or exhaust leaks from the EGR valve, EGR cooler, EGR pipe and EGR intake pipe.
Check the EGR valve, EGR cooler, EGR pipe and EGR intake pipe [Refer to ENGINE, Engine, Motor and Emission Control – Emission Control, Exhaust Gas Recirculation (EGR) System EGR PIPING DAMAGE AND INSTALLATION CONDITION CHECK].
Q: Is the check result normal?
Repair the EGR valve, the EGR cooler, the EGR pipe or the EGR intake pipe.
 
10.STEP 10. Check the EGR valve contamination, the EGR cooler contamination, the EGR pipe contamination and the EGR intake pipe contamination.
Check the EGR valve, EGR cooler, EGR pipe and EGR intake pipe for stuck closed.
Q: Is the check result normal?
Repair the EGR valve, the EGR cooler, the EGR pipe or the EGR intake pipe.
 
11.STEP 11. Check the fuel pressure.
Fuel pressure measurement (Refer to FUEL PRESSURE TEST ).
Q: Is the check result normal?
Repair or replace it.
 
12.STEP 12. Check the spark plug.
Check the number 1 cylinder spark plug, number 2 cylinder spark plug, number 3 cylinder spark plug and number 4 cylinder spark plug itself (Refer to ENGINE , Engine Electrical – On-vehicle Service SPARK PLUG CHECK AND CLEANING).
Q: Are the check result normal?
Replace the faulty spark plug (Refer to ENGINE , Engine Electrical – Ignition Coil IGNITION COIL REMOVAL AND INSTALLATION).
 
13.STEP 13. Check the ignition coil.
Check the number 1 cylinder ignition coil, number 2 cylinder ignition coil, number 3 cylinder ignition coil and number 4 cylinder ignition coil itself (Refer to ENGINE , Engine Electrical – On-vehicle Service IGNITION COIL CHECK).
Q: Are the check result normal?
Replace the faulty ignition coil (Refer to ENGINE , Engine Electrical – Ignition Coil IGNITION COIL REMOVAL AND INSTALLATION).
 
14.STEP 14. Check the compression pressure.
Check the compression pressure (Refer to ENGINE, Engine Mechanical – Engine Adjustment COMPRESSION PRESSURE CHECK ).
Q: Is the check result normal?
Repair it.
 
15.STEP 15. Check the positive crankcase ventilation system.
Check the positive crankcase ventilation system (Refer to ENGINE, Engine, Motor and Emission Control – Emission Control – Positive Crankcase Ventilation System POSITIVE CRANKCASE VENTILATION (PCV) SYSTEM CHECK).
Q: Is the check result normal?
Repair or replace it.
 
16.STEP 16. Check the purge control system.
Check the purge control system (Refer to ENGINE, Engine, Motor and Emission Control – Emission Control – Evaporative Emission System – Purge Control System Check PURGE CONTROL SYSTEM CHECK (PURGE FLOW CHECK)).
Q: Is the check result normal?
Repair or replace it.
 
17.STEP 17. Check the following items.
Check the following items.
  • Check the fuel injectors for fuel leakage.
  • Check if the fuel injectors are clogged.
Q: Are the check result normal?
Repair or replace it.
 
18.STEP 18. Check the malfunction symptoms.
Q: Does the malfunction symptom persist?
Replace the catalytic converter (Refer to ENGINE, Engine, Motor and Emission Control – Emission Control – Exhaust Gas Purification System CATALYTIC CONVERTER REMOVAL AND INSTALLATION )
Intermittent malfunction (Refer to GENERAL INFORMATION, General Information – How to Use Troubleshooting/Inspection Service Points HOW TO COPE WITH INTERMITTENT MALFUNCTIONS).