Catalytic Converter: Testing and Inspection

1. Visually inspect the components of the catalyst and exhaust system and related controls that may affect exhaust gas quality or cause backfire or loss of power.

- Leaking fuel injectors
- Damaged air inlet passages
- Inoperative Exhaust Gas Recirculation (EGR) valve
- Exhaust pipe pinched, crushed
- Damaged, loose vacuum hoses
- Incorrect idle speed
- Air filter condition
- Misrouted, damaged wiring
- Damaged coil, distributor or spark plugs
- Corroded, loose connectors


2. Exercise the wiring and connectors for the solenoids and other components for obvious problems due to looseness, corrosion, or other damage. This must be done until the engine is fully warmed so as to activate the system controls.

3. Check the vacuum lines and connections for looseness, pinching, leakage, splitting, blockage, or other damage that may cause a malfunction.

4. If a vacuum line or orifice (restrictor) blockage is suspected as the obvious cause of malfunction, correct the cause before proceeding to the next step.

5. If all checks are OK, proceed to the Pinpoint Tests.

6. If the diagnostic symptom is "Fails Emission Test", proceed to Pinpoint Test EG1.

If the symptom is "Backfires" or "Lacks Power", proceed to Pinpoint Test EX1.

NOTE: Failure to conform to the Federal Clean Air Act legal requirements for a particular vehicle and calibration is usually the result of one or more emission related system or component malfunctions.