Exhaust Gas Recirculation Flow Insufficient
P0401 means the engine computer may be seeing less EGR flow response than expected when it commands EGR operation.
Article vehicle: 2020 25 Chevrolet Silverado 2500 6.6 diesel
Read diagnostic guideDTC code
P0401: Exhaust Gas Recirculation Flow Insufficient
Vehicle-specific published guides for this diagnostic trouble code.