For 1990-2009 cars

• | Review the exhaust system description in order to familiarize yourself with the exhaust system components and the intended function of the components. Refer to Symptoms - Vehicle .

• | All diagnostics on a vehicle should follow a logical process. Strategy Based Diagnostics 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 such as, but not limited to; tailpipe extensions, headers, and exhaust cutouts. Any aftermarket exhaust system devices could affect the operation and proper performance of the exhaust system.

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

• | 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 symptom:

• | 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 Noise

• | Loud exhaust noise

| Refer to Exhaust Noise

• | Exhaust buzz, groan, humm noise

| Refer to Exhaust Noise