Emission Control System: Inspection

1. Install a clean hose into the ventilation valve.
2. Inspect the ventilation valve operation.
   1. Blow air into the cylinder head side, and check that air passes through easily.
      CAUTION: Do not suck air through the valve. Petroleum substances inside the valve are harmful.
      Fig 1: Blowing Air Into Cylinder Head Side And Checking That Air Passes Through Easily

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   2. Blow air into the intake manifold side, and check that air passes through with difficulty.
      Fig 2: Blowing Air Into Intake Manifold Side And Checking That Air Passes Through With Difficulty

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   If the operation is not as specified, replace the ventilation valve.

3. Remove the clean hose from the ventilation valve.

1. Visually check if the cap or gasket is deformed or damaged.
   Fig 3: Checking If Cap Or Gasket Is Deformed Or Damaged

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1. Visually check the charcoal canister for cracks or damage.
2. Inspect the charcoal canister operation.
   Fig 4: Inspecting Charcoal Canister Assy

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   1. Plug the vent port with a cap.
      Fig 5: Plugging Vent Port With Cap

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   2. While holding the purge port closed, blow air (1.76 kPa, 18 gf/cm² , 0.26 psi) into the EVAP port and check that air flows from the air inlet port.
      Fig 6: Blowing Air Into EVAP Port And Checking Air Flow From Air Inlet Port

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   3. Plug the air inlet port with your finger.
   4. Apply vacuum (3.43 kPa, 25.7 mmHg, 1.01 in.Hg) to the purge port, check that the vacuum decreases when the air inlet port is opened.
      Fig 7: Checking That Vacuum Decreases When Air Inlet Port Is Opened

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   5. While holding the air inlet port closed, apply vacuum (3.43 kPa, 25.7 mmHg, 1.01 in.Hg) to the EVAP port and check that air flows into the purge port.

      If the operation is not as specified, replace the charcoal canister.

      Fig 8: Applying Vacuum To EVAP Port And Checking Air Flow Into Purge Port

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   6. Remove the cap from the vent port.
3. Inspect the VSV for open circuit.
   1. Using an Ohmmeter, check the resistance between the terminals.

   Resistance: 

   TEMPERATURE AND RESISTANCE SPECIFICATION
   
   

   Temperature	Resistance
   At 20°C (68° F)	25 to 30Ω
   At 120°C (248°F)	32 to 40Ω

   If the resistance is not as specified, replace the VSV.

   Fig 9: Checking Resistance Between VSV Terminals

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4. Check the VSV for ground.
   1. Using an ohmmeter, check that there is no continuity between each terminal and the body.

   If there is continuity, replace the VSV.

   Fig 10: Checking Continuity Between Each VSV Terminal And Body

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5. Check the VSV operation.
   1. Check that air flows from port A to port B.
      Fig 11: Checking Air Flows From Port A To Port B

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   2. Apply battery positive voltage across the terminals.
   3. Check that air does not flow from port A to port B.

If operation is not as specified, replace the VSV.

Fig 12: Applying Battery Positive Voltage Across Terminals And Checking Air Flow

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1. Inspect the resistance.
   1. Using an ohmmeter, measure the resistance between the terminals.

      Resistance: 

      30 to 34Ω at 20°C (68°F) 

   If the resistance is not as specified, replace the VSV.

   Fig 13: Measuring Resistance Between Terminals

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2. Check the VSV for ground.
   1. Using an ohmmeter, check that there is no continuity between each terminal and the body.

   If there is continuity, replace the VSV.

   Fig 14: Checking For Continuity Between Each Terminal And Body

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3. Check the VSV operation.
   1. Check that air flows with difficulty from port F to port E.
      Fig 15: Checking Air Flows With Difficulty From Port F To Port E

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   2. Apply battery voltage across the terminals.
   3. Check that air flows from port F to port E.

If the operation is not as specified, replace the VSV.

Fig 16: Applying Battery Voltage Across Terminals And Checking Air Flow

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1. Using an Ohmmeter, measure the resistance between the terminals.

Standard: 

If the result is not as specified, replace the sensor.

Fig 17: Identifying Heated Oxygen Sensor (Bank1 Oxygen Sensor) Terminals

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1. Using an ohmmeter, measure the resistance between the terminals.

Standard: 

If the result is not as specified, replace the sensor.

Fig 18: Identifying Heated Oxygen Sensor (Bank1 Oxygen Sensor No. 2) Terminals

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