GM Service Manual Online
For 1990-2009 cars only

Restricted Exhaust Gasoline Engine

Step

Action

Value(s)

Yes

No

1

Check the exhaust tubing for kinks.

Is the exhaust tubing kinked?

--

Go to Step 2

Go to Step 3

2

Repair the kinks in the exhaust system or replace the exhaust tubing.

Is the exhaust system restricted?

--

Go to Step 3

System OK

3

Check for restrictions within the muffler. Refer to Restricted Exhaust System Check in Engine Controls.

Are there any restrictions within the muffler?

--

Go to Step 4

Go to Step 5

4

Remove the muffler and examine it. If the muffler is damaged and cannot be repaired, replace the muffler.

Is the exhaust system restricted?

--

Go to Step 5

System OK

5

Inspect the end of the tailpipe for any obstructions.

Is the exhaust system restricted?

--

Go to Step 6

System OK

6

Remove the obstruction from the end of the tailpipe. If the end of the tailpipe is crimped, straighten the outlet.

Is the exhaust system restricted?

--

Go to Step 7

System OK

7

Inspect the catalytic converter for restrictions that may have occurred as a result of engine malfunction. Refer to Restricted Exhaust System Check in Engine Controls.

Is the catalytic converter restricted?

--

Go to Step 8

System OK

8

If the catalytic converter is damaged and cannot be repaired, replace the catalytic converter.

Is the exhaust system restricted?

--

--

System OK

Restricted Exhaust Diesel Engine

Step

Action

Value(s)

Yes

No

1

Check the exhaust tubing for kinks.

Is the exhaust tubing kinked?

--

Go to Step 2

Go to Step 3

2

Repair the kinks in the exhaust system or replace the exhaust tubing.

Is the exhaust system restricted?

--

Go to Step 3

System OK

3

Check for restrictions within the muffler. Refer to Restricted Exhaust System Check in Engine Controls.

Are there any restrictions within the muffler?

--

Go to Step 4

Go to Step 5

4

Remove the muffler and examine it. If the muffler is damaged and cannot be repaired, replace the muffler.

Is the exhaust system restricted?

--

Go to Step 5

System OK

5

Inspect the end of the tailpipe for any obstructions.

Is the exhaust system restricted?

--

Go to Step 6

System OK

6

Remove the obstruction from the end of the tailpipe. If the end of the tailpipe is crimped, straighten the outlet.

Is the exhaust system restricted?

--

Go to Step 7

System OK

7

Inspect the catalytic converter for restrictions that may have occurred as a result of engine malfunction. Refer to Restricted Exhaust System Check in Engine Controls.

Is the catalytic converter restricted?

--

Go to Step 8

--

8

    • Occasional higher load operation should prevent the catalytic converter from being restricted.
    • Repeated full throttle accelerations may correct an existing condition.
    • Correct the engine malfunction.

Is the exhaust system restricted?

--

--

System OK