P1491moderate severityPowertrain
EGR Valve Lift Insufficient
on 1990-2005 Acura NSX 3.0L V6 · AWD
What this code means
The EGR valve is not lifting enough to allow commanded exhaust gas recirculation.
Symptoms
- CEL
- Increased NOx
- Failed emissions
- Engine knock possible
- Rough idle
Common causes
- Carbon buildup
- Faulty EGR valve
- Clogged passages
- Vacuum supply issue
Diagnostic steps
- Clean EGR passages
- Test EGR valve
- Check vacuum supply
- Inspect position sensor
Repair notes
Clean EGR system or replace valve.
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