P2001high severityPowertrain
NOx Trap Efficiency Below Threshold Bank 2
on 1997 BMW 318ti E36 1.9L I4 M44 · RWD
What this code means
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.
Other Powertrain codes on this vehicle
P0001
Fuel Volume Regulator Control Circuit/Open
P0002
Fuel Volume Regulator Control Circuit Range/Performance
P0003
Fuel Volume Regulator Control Circuit Low
P0004
Fuel Volume Regulator Control Circuit High
P0010
Intake Camshaft Position Actuator Circuit/Open Bank 1
P0011
Intake Camshaft Position Timing Over-Advanced Bank 1
P0012
Intake Camshaft Position Timing Over-Retarded Bank 1
P0013
Exhaust Camshaft Position Actuator Circuit/Open Bank 1
P0014
Exhaust Camshaft Position Timing Over-Advanced Bank 1
P0015
Exhaust Camshaft Position Timing Over-Retarded Bank 1