P0401 means exhaust gas recirculation flow insufficient. The EGR system isn't recirculating enough exhaust gas back into the intake. EGR lowers combustion temperatures and NOx e
You can keep driving — get it checked when convenient.
The EGR system isn't recirculating enough exhaust gas back into the intake. EGR lowers combustion temperatures and NOx emissions — when it under-flows, you may get pinging/knocking and a check engine light.
The classic cause — carbon buildup blocks flow.
Stuck closed.
Bad feedback to the computer.
No vacuum to open the valve.
Carbon-choked passages.
Typically $150–$500
EGR cleaning typically $150–$300; valve replacement typically $250–$500. Estimates vary by vehicle. Costs are estimates and vary by vehicle, location, and shop.
Safe to drive. You might notice light pinging under load. Fix at your convenience — mainly an emissions issue.
Typically $150–$500. EGR cleaning typically $150–$300; valve replacement typically $250–$500. Estimates vary by vehicle.
You can keep driving — get it checked when convenient.
The most common cause is carbon-clogged egr valve or passages. The classic cause — carbon buildup blocks flow.