Catalytic Converter: Testing and Inspection

The proper function of the catalytic converter is continuously evaluated by the On-Board Diagnostic II (OBD II) system. The OBD II system uses an oxygen sensor in the outlet of each catalytic converter to determine if the converter is functioning. The signals from the Oxygen sensors up stream of the catalytic converters are compared to the signals from the Oxygen sensors down stream of the catalytic converters and the OBD II system then determines if the converters are functioning properly.