P1491
EGR Valve Lift Insufficient
1998-1998 Acura TL 2.5L I5
Moderate SeverityPowertrain
The 1998 Acura TL is equipped with a 2.5L inline-5 engine. Below you'll find detailed p1491 diagnostic code information including labor time estimates, cost ranges, and technician notes specific to this engine configuration.
Description
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
- 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
P1491 on Other Vehicles
Common Questions
What does code P1491 mean on a 1998-1998 Acura TL?
P1491 stands for "EGR Valve Lift Insufficient". The EGR valve is not lifting enough to allow commanded exhaust gas recirculation.
What are the symptoms of P1491 on a Acura TL?
Common symptoms of P1491 include: CEL, Increased NOx, Failed emissions, Engine knock possible, Rough idle.
What causes P1491 on a 1998-1998 Acura TL?
Common causes of P1491 include: Carbon buildup, Faulty EGR valve, Clogged passages, Vacuum supply issue.
Last updated: March 2026