Diagnostic Aids
For dual exhaust systems a quick check of exhaust flow will help determine which side of the exhaust system is restricted. The side that has less exhaust flow is the side that will be suspect, and diagnosis should begin there.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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The exhaust system has very low backpressure under normal conditions. If the exhaust system is restricted, a significant increase in exhaust pressure is noticed on the J 35314. Note: Removing the O2S sensor may set a DTC. When finishing this diagnostic table, be sure to clear all codes.
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This step will isolate the catalytic converter from the remainder of the exhaust system.
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Confirming that the condition has been fixed is essential. If the symptom still exists and the vehicle has a dual exhaust system, proceed to Step 2 and repeat diagnostic procedure on the opposite exhaust pipe.
Step | Action | Values | Yes | No | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
1 | Did you verify the customer's complaint? | -- | Go to Step 2 | -- | ||||||||
2 |
Caution: While engine is operating, the exhaust system will become extremely hot. To prevent burns avoid contacting a hot exhaust system.
Did you find and correct a condition? | -- | Go to Step 7 | Go to Step 3 | ||||||||
3 | Is the system equipped with dual exhaust? | -- | Go to Diagnostic Aids | Go to Step 4 | ||||||||
Does the reading exceed the specified value? | 14 kPa (2 psi) | Go to Step 5 | Go to Step 7 | |||||||||
Inspect the exhaust system for the following conditions:
Did you find and correct the condition? | -- | Go to Step 7 | Go to Step 6 | |||||||||
6 | Replace the catalytic converter. Refer to Catalytic Converter Replacement . Is replacement complete? | -- | Go to Step 7 | -- | ||||||||
Did you correct the condition? | -- | System OK | Go to Step 2 |
