2017 Subaru P0401: What It Means & Is It Safe to Drive?
P0401 on the 2017 Subaru: Exhaust Gas Recirculation Flow Insufficient. Here's what it means, what usually causes it, what repairs typically cost, and whether it's safe to keep driving.
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What this code means
The EGR system is not flowing enough exhaust gas. Usually due to carbon buildup or a stuck valve.
Common causes on the 2017 Subaru
- Carbon-clogged EGR valve or passages
- Faulty EGR valve
- Faulty EGR position or differential pressure sensor
Symptoms
- Check Engine Light
- Rough idle, hesitation
- Knock under acceleration
Typical fixes
- Clean or replace EGR valve
- Clean EGR passages in intake
- Replace EGR sensor if applicable
Repair cost range
For a 2017 Subaru, repairs for P0401 typically fall between $150 and $600, depending on the root cause and labor rates in your area.
Known issues on Subaru
P0401 on Subaru's EZ30 H6 is typically a sticky EGR valve rather than severe passage blockage. Clean the valve and verify vacuum actuation. If the EGR valve diaphragm is cracked, vacuum will bleed off and the valve won't open to full flow.
Most commonly affected models
Outback H6 EZ30 2001–2009Legacy H6 EZ30 2001–2009