P0401Exhaust Gas Recirculation (EGR) Flow Insufficient Detected
The EGR system is not recirculating enough exhaust gas, which raises NOx emissions.
This code also has a manufacturer-specific definition:
Can I keep driving? Yes
You can keep driving normally. Schedule a check soon so emissions and performance are not affected.
Sistema Afectado
Sistema de Escape · Catalizador y sensores O₂
La falla se localiza en la línea de escape: catalizador, sondas lambda (O₂) o sistema EGR.
Espacio para vendedores de repuestos
Aún no hay un anunciante en este espacio.
Symptoms You Will Notice
What you may observe when this code appears
- Engine knocking
- Increased emissions
- Reduced performance at low speed
Possible Causes
The components or conditions that trigger this code
- 1EGR valve clogged with carbon
- 2Blocked EGR passages
- 3Faulty EGR position sensor
- 4Damaged EGR solenoid
How to Fix It — Step by Step
Recommended diagnostic and repair procedure
- 1Clean the EGR valve with carburetor cleaner
- 2Clean the recirculation passages
- 3Check the solenoid operation
- 4Replace the valve if needed
Note: This information is for general reference. For precise diagnostics and safety repairs, always consult a certified mechanic.
Estimated Cost
Approximate range in USD (varies by region and shop)
Varies by diagnosis
* Diagnosis only: $50–$150
Quick Info
Dig Deeper
Videos, images and service manuals
Have Another Code?
Look it up directly: