OBD-II TROUBLE CODE GUIDE
P0401: Exhaust Gas Recirculation Flow Insufficient
The expected response was not detected when EGR flow was commanded.
What P0401 means
The expected response was not detected when EGR flow was commanded.
Common possible causes
- Carbon-blocked EGR passages
- Sticking EGR valve
- Vacuum-control or feedback-sensor problem
What to check first
Record all stored and pending codes and freeze-frame data before clearing anything. Inspect relevant wiring, connectors, hoses, fluid levels, and obvious damage. Use vehicle-specific service information and test the affected system before purchasing parts.
A code is not a parts order. Several faults can create the same code, and replacing the component named in a code description may not correct the underlying problem.
Look up P0401 for my vehicle