GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2000 🢒 Park Avenue 🢒 Engine 🢒 Engine Controls - 3.8L 🢒 Restricted Exhaust System Check

Restricted Exhaust System Check

Step

Action

Values

Yes

No

1

Did you perform the Powertrain On-Board Diagnostic (OBD) System Check?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check .

2
  1. Remove HO2S 1. Refer to Heated Oxygen Sensor Replacement .
  2. In place of HO2S 1, install J 35314-A Exhaust Back Pressure Tester.
  3. Start the engine.
  4. With the engine idling at normal operating temperature, observe the exhaust system back pressure reading on the GAUGE.

Does the reading exceed the specified value?

8.6 kPa (1.25 psi)

Go to Step 4

Go to Step 3

3
  1. With the exhaust each pressure tester or equivalent in place of HO2S 1, increase engine speed to 2000 rpm.
  2. Observe the exhaust system back pressure reading on the GAUGE.

Does the reading exceed the specified value?

20.7 kPa (3 psi)

Go to Step 4

System OK

4
  1. Reinstall HO2S 1. Refer to Heated Oxygen Sensor Replacement .
  2. Remove HO2S 2. Refer to Heated Oxygen Sensor Replacement .
  3. In place of HO2S, install exhaust back pressure tester J 35314-A Exhaust Back Pressure Tester.
  4. Engine at normal operating temperature.
  5. Increase engine speed to 2000 rpm.
  6. Observe the exhaust system back pressure reading on the GAUGE.

Does the reading exceed the specified value?

20.7 kPa (3 psi)

Go to Step 5

Go to Step 6

5

Locate and repair the restriction in the exhaust system past the three way catalytic converter. Refer to Restricted Exhaust in Engine Exhaust. Possible faults include:

    • Collapsed pipe
    • Heat distress
    • Internal muffler failure

Is action complete?

--

Go to Step 7

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6

Replace the three way catalytic converter. Refer to Catalytic Converter Replacement in Engine Exhaust.

Is action complete?

--

Go to Step 7

--

7
  1. Remove HO2S 1. Refer to Heated Oxygen Sensor Replacement .
  2. In place of HO2S 1, install J 35314-A exhaust back pressure tester.
  3. Engine idling at normal operating temperature.
  4. Observe the exhaust system back pressure reading on the GAUGE.

Does the reading exceed the specified value?

8.6 kPa (1.25 psi)

Go to Step 4

Go to Step 8

8
  1. With exhaust back pressure tester in place of HO2S 1, increase engine speed to 2000 rpm.
  2. Observe the exhaust system back pressure reading on the GAUGE.

Does the reading exceed the specified value?

20.7 kPa (3 psi)

Go to Step 5

System OK