Catalytic Converter: Testing and Inspection

1. Check catalytic converter for physical damage, or exhaust leaks.
2. Check exhaust system for restriction.
3. Replace converter if damaged, leaking, or restricted.

EXHAUST RESTRICTION CHECK:

EXHAUST PRESSURE METHOD

1. Install exhaust backpressure tester in place of Oxygen sensor or AIR check valve.
2. Start engine and idle. Note exhaust pressure, should not exceed 8.6 KPa (1.25 psi).
3. Run engine at approx. 2,000 rpm. Note exhaust pressure, should not exceed 20.7 KPa (3 psi).

MANIFOLD VACUUM METHOD

1. Connect vacuum gauge to manifold vacuum source.
2. Start engine and idle. Note vacuum reading, and record.
3. Run engine at approx. 2,000 rpm with no load. Note vacuum at steady engine speed. If vacuum is less than previous (idle) reading by greater than 75mmHg (3"Hg), a restricted exhaust system is indicated.