B - Charts

Proper Diagnosis for a restricted exhaust system is essential before any components are replaced.

DIAGNOSIS:

1. With the engine idling at normal operating temperature, observe the exhaust system back pressure reading on the gage. Reading should not exceed 7.8 kPa (1.13 psi).

2. Increase engine speed to 2000 revolution per minute and observe gage. Reading should not exceed 14.6 kPa (2.11 psi).

3. If the backpressure at either speed exceeds specification, a restricted exhaust system is indicated.

4. Inspect the entire exhaust system for a collapsed pipe, heat distress, or possible internal muffler failure.

5. If there are no obvious reasons for the excessive back pressure, the three way catalytic converter is suspected to be restricted and should be replaced.