For 1990-2009 cars

• | Review the Exhaust System Description and Operation in order to familiarize yourself with the system functions. Refer to Exhaust System Description .

• | All diagnoses on a vehicle should follow a logical process. Strategy Based Diagnosis is a uniform approach for repairing all systems. The diagnostic flow is the place to start when repairs are necessary and may always be used in order to resolve a system problem. For a detailed explanation, refer to Strategy Based Diagnosis .

### Visual/Physical Inspection

• | Inspect for aftermarket or non-OEM devices including, but not limited to tailpipe extensions, headers, and exhaust cutouts. This could affect the operation and proper performance of the exhaust system.

• | Verify the exact operating conditions under which the problem exists. Note factors such as engine RPM, engine temperature, engine load, and frequency of the problem.

• | Inspect the easily accessible or visible system components for obvious damage or conditions which could cause any symptom.

### Intermittent

Test the vehicle under the same conditions that the customer reported in order to verify the system is operating as designed.

### Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptoms:

• | Loss of power, refer to Restricted Exhaust .

• | Poor acceleration, refer to Restricted Exhaust .

• | Poor fuel economy, refer to Restricted Exhaust .

• | Excessive smoke-diesel, refer to Restricted Exhaust .

• | Exhaust hissing noise, refer to Exhaust Leakage .

• | Exhaust popping noise, refer to Exhaust Leakage .

• | Exhaust rattle noise, refer to Exhaust Leakage .

• | Loud exhaust noise, refer to Exhaust Noise .

• | Exhaust buzz, groan, hum noise, refer to Exhaust Noise .