P0401 — Exhaust Gas Recirculation Flow Insufficient Detected
Category: Powertrain Severity: Medium
Updated:
DTC code P0401 means: Exhaust Gas Recirculation Flow Insufficient Detected. It falls under the "Powertrain" category, with an estimated severity of Medium. Common causes include faulty EGR valve, clogged EGR passages and faulty EGR position sensor; it's worth confirming the diagnosis before replacing parts.
Possible causes
- Faulty EGR valve
- Clogged EGR passages
- Faulty EGR position sensor
- Vacuum leak
Symptoms
- Jerking at low RPM
- Loss of power
- Black smoke
- Check engine light
How to diagnose it step by step
- Command the EGR with a scan tool and watch for an idle change.
- Remove and clean the EGR valve.
- Clean the EGR passages.
- Check the DPFE sensor and its hoses.
- Replace the valve if damaged.
How to fix it
Clean the EGR valve and its passages; if it doesn't respond, replace it.
Estimated repair cost
Cleaning: $100–250. EGR valve: $200–650.
Frequently asked questions
What does DTC code P0401 mean?
Exhaust Gas Recirculation Flow Insufficient Detected.
Is code P0401 serious?
Severity Medium. Not urgent, but worth diagnosing to avoid bigger damage.
Can I keep driving with code P0401?
Yes; there may be pinging and high NOx emissions.
Related codes
P0400 P0402 P0403 P0404 P0405 P0406 P0410 P0411 P0420 P0421
Refine by car make
- Audi P0401: EGR valve clogged (typical on TDI).
- BMW P0401: EGR valve clogged (typical on diesel).
- Citroën P0401: EGR valve stuck (typical on HDI).
- Dacia P0401: EGR valve clogged (typical on dCi).
- Fiat P0401: EGR valve stuck (typical on JTD/Multijet).
- Ford P0401: EGR valve stuck or DPFE sensor.
- Honda P0401: EGR valve stuck.
- Mercedes-Benz P0401: EGR valve clogged (typical on CDI).
- Nissan P0401: EGR valve clogged (typical on dCi).
- Opel P0401: EGR valve stuck (typical on CDTI).
- Peugeot P0401: EGR valve stuck (typical on HDI).
- Renault P0401: EGR valve clogged (typical on dCi).
- Toyota P0401: EGR valve stuck (typical on D-4D).
- Volkswagen P0401: EGR valve clogged with carbon (typical on TDI).
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