SEAL-O-RING 4D1577 - Caterpillar

Use this procedure in order to troubleshoot a high outlet temperature for the catalytic converter. Also, use this procedure if one of the following diagnostic codes is active. Refer to Troubleshooting, "Diagnostic Trouble Codes" for information about diagnostic trouble codes. Access the engine monitoring system on Caterpillar Electronic Technician (ET) in order to view the current trip points for these engine events. For information on the engine monitoring system, refer to Troubleshooting, "Engine Monitoring Parameters".
Table 1
Engine Events
J1939 Code and Description Conditions which Generate the Code System Response
4290-0 Aftertreatment #1 Three Way Catalytic Converter Outlet Gas Temperature : High - most severe (3) The outlet temperature for the catalytic converter is above the trip point for the programmed delay time. The code is logged.
The red stop lamp is illuminated.
The engine is shut down.
4290-15 Aftertreatment #1 Three Way Catalytic Converter Outlet Gas Temperature : High - least severe (1) The code is logged.
The amber warning lamp is illuminated. Probable Causes
Damaged catalyst substrate
Improper air/fuel ratioRecommended Actions
Damaged Catalyst Substrate
Mechanical damage to the catalyst substrate may cause high exhaust temperatures at the outlet of the catalytic converter. The catalyst substrate may become fractured or broken by mechanical shock, excessive vibration, or excessive heat.Disassemble the catalytic converter and inspect the catalyst substrate. Refer to Testing and Adjusting, "Catalytic Converter Substrate - Inspect", for information that is related to visual inspection of the catalyst substrate.Improper Air/Fuel Ratio
If the engine is running rich, unburned fuel may accumulate in the catalytic convertor. Eventually, this unburned fuel ignites. As the fuel burns in the catalytic convertor, the outlet temperature spikes to a point that is above the operating limits of the convertor. After the fuel burns off, the outlet temperature decreases to the normal operating temperature and the cycle repeats.The heating value of the fuel may have changed. Check the fuel quality and ensure that the engine timing is within specifications.