P0401
EGR A Flow Insufficient Detected
Powertrain · Generic (all makes)System: Emissions
Safe to drive short term. Book a repair.
Likely causes
- Carbon-clogged EGR passages
- Stuck EGR valve
- Faulty EGR position sensor or vacuum solenoid
What to check first
Clean the EGR valve and passages before replacing parts; carbon buildup is the usual cause.
Typical repair cost
$150 – $700
Independent-shop parts and labor for the usual fix. Your price depends on the actual cause and the vehicle.
Next step
General information, not a diagnosis of your vehicle. Repair costs are typical shop ranges, not quotes.