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

Restricted Exhaust System Check

Step

Action

Value(s)

Yes

No

1

Was the On-Board Diagnostic (OBD) System Check performed?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2
  1. Remove the HO2S 1. Refer to Heated Oxygen Sensor Replacement .
  2. Install a J 35314-A exhaust back pressure tester in place of the HO2S 1.
  3. Start the engine.
  4. With the engine idling at a normal operating temperature and the transaxle in Park, observe the exhaust system back pressure reading on the gauge.

Is the pressure more than the specified value?

8.6 kPa (1.25 psi)

Go to Step 4

Go to Step 3

3
  1. Leave the transaxle in Park.
  2. With the exhaust back pressure tester, or equivalent, in place of the HO2S 1, increase the engine speed to 2000 RPM.
  3. Observe the exhaust system back pressure reading on the gauge.

Is the pressure more than the specified value?

20.7 kPa (3 psi)

Go to Step 4

System OK

4
  1. Reinstall the HO2S 1.
  2. Remove the HO2S 2. Refer to Heated Oxygen Sensor Replacement .
  3. Install the J 35314-A exhaust back pressure tester in place of the HO2S.
  4. Allow the engine to idle at a normal operating temperature.
  5. Leave the transaxle in Park.
  6. Increase the engine speed to 2000 RPM.
  7. Observe the exhaust system back pressure reading on the gauge.

Is the pressure more than 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 3-way catalytic converter. Possible malfunctions include:

    • A collapsed pipe
    • Heat distress
    • An internal muffler failure. Refer to Muffler Replacement in Engine Exhaust.

Did you complete the repair?

--

Go to Step 7

--

6

Replace the 3- way catalytic converter. Refer to Catalytic Converter Replacement in Engine Exhaust.

Did you complete the repair?

--

Go to Step 7

--

7
  1. Remove the HO2S 1. Refer to Heated Oxygen Sensor Replacement .
  2. Install the J 35314-A exhaust back pressure tester in place of the HO2S 1.
  3. Leave the transaxle in Park.
  4. Allow the engine to idle at a normal operating temperature.
  5. Observe the exhaust system back pressure reading on the gauge.

Is the pressure more than the specified value?

8.6 kPa (1.25 psi)

Go to Step 4

Go to Step 8

8
  1. Leave the transaxle in Park.
  2. With the exhaust back pressure tester in place of the HO2S 1, increase the engine speed to 2000 RPM.
  3. Observe the exhaust system back pressure reading on the gauge.

Is the pressure more than the specified value?

20.7 kPa (3 psi)

Go to Step 5

System OK