What does code P0401 mean on a Infiniti and is it safe to drive?
P0401: Exhaust Gas Recirculation Flow Insufficient. Here's what it means on your Infiniti, what usually causes it, what repairs typically cost, and how safe it is to keep driving.
PowertrainMedium urgency
What this code means
The EGR system is not flowing enough exhaust gas. Usually due to carbon buildup or a stuck valve.
Common causes for your Infiniti
- 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 Infiniti, repairs for P0401 often fall between $150 and $600, depending on the cause and whether you use OEM or aftermarket parts. Labor rates vary by location.
Known issues on Infiniti
Infiniti VQ35 EGR insufficient flow is primarily caused by carbon buildup in the EGR valve passages and intake ports. Cleaning the EGR valve and the intake port deposits restores adequate flow on most VQ engines without requiring replacement.
Most commonly affected models
G35 2003–2007M35 2006–2010FX35 2003–2008