Lean NOx Trap (LNT) Desulfation Failure
2003-2007 Dodge Ram 2500 5.9L I6 Cummins Diesel
Description
The lean NOx trap desulfation process has failed to restore NOx conversion efficiency. The LNT requires periodic high-temperature desulfation to remove sulfur compounds.
Symptoms
- Check Engine Light
- Increased NOx emissions
- LNT warning
- Failed emissions test
- Reduced power may occur
- Fuel economy decrease from failed desulfation attempts
Common Causes
- Fuel sulfur content too high
- LNT catalyst degradation
- Exhaust temperature insufficient for desulfation
- Fuel injection issue during desulfation
- LNT poisoned beyond recovery
Diagnostic Steps
- Check LNT NOx efficiency before and after desulfation attempt
- Monitor exhaust temperature during desulfation
- Check fuel quality
- Inspect fuel injectors for desulfation function
- Review desulfation attempt history
Repair Notes
Attempt forced desulfation at controlled temperatures. Replace LNT if desulfation cannot restore efficiency. Use ultra-low sulfur diesel fuel.
Related Codes
Other Powertrain Codes
- P0001Fuel Volume Regulator Control Circuit/Open
- P0002Fuel Volume Regulator Control Circuit Range/Performance
- P0003Fuel Volume Regulator Control Circuit Low
- P0004Fuel Volume Regulator Control Circuit High
- P0010Intake Camshaft Position Actuator Circuit/Open Bank 1
- P0011Intake Camshaft Position Timing Over-Advanced Bank 1
- P0012Intake Camshaft Position Timing Over-Retarded Bank 1
- P0013Exhaust Camshaft Position Actuator Circuit/Open Bank 1
- P0014Exhaust Camshaft Position Timing Over-Advanced Bank 1
- P0015Exhaust Camshaft Position Timing Over-Retarded Bank 1
P3881 on Other Vehicles
Dodge Ram 2500
1994-2007 5.9L I6 Cummins Diesel
Dodge Ram 2500
1994-2008 5.9L I6 Cummins Diesel
Dodge Ram 2500
2007-2008 6.7L I6 Cummins Diesel
Dodge Ram 2500
2007-2009 6.7L I6 Cummins Diesel
Dodge Ram 3500
1994-2007 5.9L I6 Cummins Diesel
Dodge Ram 3500
1994-2024 6.7L I6 Cummins Diesel
Dodge Ram 3500
2007-2008 6.7L I6 Cummins Diesel
Dodge Ram 3500
2007-2009 6.7L I6 Cummins Diesel
Common Questions
What does code P3881 mean on a 2003-2007 Dodge Ram 2500?
P3881 stands for "Lean NOx Trap (LNT) Desulfation Failure". The lean NOx trap desulfation process has failed to restore NOx conversion efficiency. The LNT requires periodic high-temperature desulfation to remove sulfur compounds.
What are the symptoms of P3881 on a Dodge Ram 2500?
Common symptoms of P3881 include: Check Engine Light, Increased NOx emissions, LNT warning, Failed emissions test, Reduced power may occur, Fuel economy decrease from failed desulfation attempts.
What causes P3881 on a 2003-2007 Dodge Ram 2500?
Common causes of P3881 include: Fuel sulfur content too high, LNT catalyst degradation, Exhaust temperature insufficient for desulfation, Fuel injection issue during desulfation, LNT poisoned beyond recovery.