Restricted Exhaust System Check. Buick GL7 (Export) 2000

For 1990-2009 cars

#### 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 the HO2S 1. Refer to Heated Oxygen Sensor Replacement .
2. Install the J 35314-A exhaust back pressure tester, or equivalent, in place of the HO2S 1.
3. Allow the engine to idle at a normal operating temperature.
4. Observe the 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 pressure tester in place of the HO2S 1, increase the engine speed to 2000 RPM.
2. Observe the back pressure reading on the gage.

Does the reading exceed the specified value?

20.7 kPa (3 psi)

Go to Step 4

System OK

4

Repair a restriction in the exhaust system. Possible faults include the following:

• | A collapsed pipe

• | Heat distress

• | An internal muffler failure

• | A plugged catalytic converter

Is the action complete?

--

Go to Step 5

--

5

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

Does the reading exceed the specified value?

20.7 kPa (3 psi)

Go to Step 2

System OK