P0401: Exhaust Gas Recirculation (EGR) Flow Insufficient Detected

The EGR system is not flowing enough exhaust gas back into the intake.

Low Severity

$100 – $500

Typical repair cost range

Get Estimate for My Car

Can I Keep Driving with Code P0401?

Yes, but expect poor fuel economy and possible failed emissions tests.

What P0401 Means

The EGR valve recirculates a small amount of exhaust into the intake to reduce combustion temperatures and emissions. P0401 means it is not flowing enough, usually due to carbon buildup or a stuck valve.

Common Causes

Diagnostic Tips

Often resolved by cleaning the EGR valve and passages.
On Ford vehicles, check the DPFE sensor first, it is a known failure point.

Skip the Guesswork

Get an AI estimate for the most likely repair on your exact car, in under a minute.

Get My Free Estimate

Frequently Asked Questions

Will P0401 fail emissions?

Yes in most states. EGR is part of the emissions control system.