NOx Trap Efficiency Below Threshold Bank 2
2009-2009 Mitsubishi Eclipse 2.4L I4
The 2009 Mitsubishi Eclipse is equipped with a 2.4L inline-4 engine. Below you'll find detailed p2001 diagnostic code information including labor time estimates, cost ranges, and technician notes specific to this engine configuration.
Description
The NOx storage catalytic converter on bank 2 is not efficiently reducing nitrogen oxides.
Symptoms
- Check engine light
- Failed emissions
- Slight power loss
Common Causes
- Degraded NOx trap bank 2
- Sulfur poisoning
- Exhaust leak
- NOx sensor fault
Diagnostic Steps
- Check NOx sensor output bank 2
- Compare to bank 1
- Inspect exhaust for leaks
Repair Notes
Replace NOx trap bank 2 if regeneration fails.
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
P2001 on Other Vehicles
Mitsubishi 3000GT
1996-1996 3.0L V6 Twin Turbo
Mitsubishi 3000GT
1997-1997 3.0L V6 Twin Turbo
Mitsubishi 3000GT
1998-1998 3.0L V6 Twin Turbo
Mitsubishi 3000GT
1999-1999 3.0L V6 Twin Turbo
Mitsubishi Colt JP
2002-2002 1.3L I4 4A90
Mitsubishi Colt JP
2002-2002 1.5L I4 4A91
Mitsubishi Colt JP
2003-2003 1.3L I4 4A90
Mitsubishi Colt JP
2003-2003 1.5L I4 4A91
Common Questions
What does code P2001 mean on a 2009-2009 Mitsubishi Eclipse?
P2001 stands for "NOx Trap Efficiency Below Threshold Bank 2". The NOx storage catalytic converter on bank 2 is not efficiently reducing nitrogen oxides.
What are the symptoms of P2001 on a Mitsubishi Eclipse?
Common symptoms of P2001 include: Check engine light, Failed emissions, Slight power loss.
What causes P2001 on a 2009-2009 Mitsubishi Eclipse?
Common causes of P2001 include: Degraded NOx trap bank 2, Sulfur poisoning, Exhaust leak, NOx sensor fault.
Last updated: March 2026