GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1999 🢒 Malibu 🢒 Engine 🢒 Engine Controls - 3.1L (LG8) 🢒 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 HO2S 1. Refer to Heated Oxygen Sensor (HO2S) Replacement .
  2. Install Exhaust Back pressure tester J 35314-A in place of HO2S 1.
  3. Allow the engine to idle at the normal operating temperature.
  4. Observe the exhaust system back pressure reading on the gauge.

Does reading exceed the specified value?

8.6 kPa (1.25 psi)

Go to Step 4

Go to Step 3

3
  1. With Exhaust Back pressure tester J 35314-A in place of HO2S 1, increase engine speed to 2000 rpm.
  2. Observe the exhaust system back pressure reading on the gage.

Does 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 (HO2S) Replacement .
  2. Remove HO2S 2. Refer to Heated Oxygen Sensor (HO2S) Replacement .
  3. Install Exhaust Back pressure tester J 35314-A in place of HO2S 2.
  4. Engine at normal operating temperature.
  5. Increase engine speed to 2000 rpm.
  6. Observe the exhaust system back pressure reading on the gage.

Does reading exceed the specified value?

20.7 kPa (3 psi)

Go to Step 5

Go to Step 6

5

Repair restriction in the exhaust system past the Three-Way Catalytic Converter Possible faults include:

    •  Collapsed pipe
    •  Heat distress
    •  Internal muffler failure

Is the action complete?

--

Go to Step 7

--

6

Replace the Three-Way Catalytic Converter. Refer to Catalytic Converter Replacement .

Is the action Complete?

--

Go to Step 7

--

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

Does reading exceed the specified value?

8.6 kPa (1.25 psi)

Go to Step 4

Go to Step 8

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

Does reading exceed the specified value?

20.7 kPa (3 psi)

Go to Step 5

System OK