EGR Insufficient Flow Detected
Powertrain Code · Medium
What does P0401 mean?
The EGR system is not flowing enough exhaust gas back into the intake. Usually caused by carbon buildup in the EGR valve or passages, or a failed EGR valve.
System: EGR System
P0401 is a powertrain diagnostic trouble code indicating egr insufficient flow detected. This code is classified as medium severity, which means: schedule service — affects performance or emissions. We have vehicle-specific diagnostic data for 43 models below. Select your vehicle for tailored causes, symptoms, and repair cost estimates.
Diagnostic data on this page is compiled from publicly available repair resources and technical service bulletins. Always have a qualified mechanic confirm the diagnosis before authorizing repairs on your vehicle.
See causes, symptoms, and repair costs for P0401 on specific vehicles: