P0430-CATALYST EFFICIENCY (BANK 2)
Click to display a list of tools used in this procedure
For a complete wiring diagram, refer to the Wiring Information
Theory of Operation
The State of Change (SOC) catalyst monitor uses the signals from both the upstream and downstream O2 sensors to detect aging of the catalyst. Based on the fact that when a catalyst ages, it loses some of its Oxygen Storage Capacity (OSC). As a result, part of the untreated exhaust gases can breakthrough the catalyst and causes the downstream O2 sensor to deviate from its neutral (Stoichiometric) position. By observing the activities in the downstream O2 signal, the degradation level of catalyst can be detected. In general, the higher the downstream O2 sensor SOC value, the more exhaust gas breakthrough and the lower the OSC of the catalytic converter.
- When Monitored: ECT above 70° C (158° F), engine RPM between 1400 and 2300, vehicle speed between 64 and 96 kph (40 and 60 mph), and engine run time greater than three minutes.
- Set Condition: If the final State of Change index is within the calibrated fail threshold. Two trip fault. Three good trips to turn off the MIL.
(K902) O2 RETURN UPSTREAM CIRCUIT SHORTED TO GROUND(K904) O2 RETURN DOWNSTREAM CIRCUIT SHORTED TO GROUND(K902) O2 RETURN UPSTREAM CIRCUIT OPEN(K904) O2 RETURN DOWNSTREAM CIRCUIT OPENEXHAUST LEAKENGINE MECHANICAL CONDITIONAGING O2 SENSORCATALYTIC CONVERTER
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
NOTE:A new rear O2 Sensor along with an aging front O2 Sensor may cause the DTC to set. Review the repair history of the vehicle before continuing.
NOTE:If an O2 Sensor DTC set along with the Catalytic Converter Efficiency DTC diagnose the O2 Sensor DTC(s) before continuing.
NOTE:Check for contaminants that may have damaged the O2 Sensor and Catalytic Converter: contaminated fuel, unapproved silicone, oil and coolant, repair necessary.
1.Start the engine.2.Allow the engine to reach normal operating temperature.3.With a scan tool, select View DTCs.
NOTE:It may be necessary to drive the vehicle to meet the conditions to set this DTC, try to repeat the conditions in which the fault originally set by reviewing the Freeze Frame data.
Some info from the manual. Did you bang on the converter with a soft hammer? Sometimes when a converter goes bad you will hear the honey comb inside ratteling around. If you replace the converter it is a good idea to replace the O2 sensors also.