Catalytic Converter: Testing and Inspection

DIAGNOSIS:

1. With the engine idling at normal operating temperature, observe the exhaust system backpressure reading on the gauge. The reading should not exceed 1.25 psi or 8.6 kPa. Increase engine speed to 2000 rpm and observe gauge. The reading should not exceed 3 psi or 20.7 kPa.

2. If the backpressure exceeds the given specifications, a restricted exhaust system is indicated.

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

4. If there are no obvious reasons for the excessive backpressure, a restricted catalytic converter should be suspected, and replaced.