P0401 on Ford
Exhaust Gas Recirculation Flow Insufficient
P0401 on Ford vehicles indicates exhaust gas recirculation flow insufficient. Au7o has documented this code across 4 Ford models — most commonly on Explorer, F-150, F-250 Super Duty. This code means the Exhaust Gas Recirculation (EGR) system is not flowing enough exhaust back into the engine. The EGR system recirculates a small amount of exhaust into the intake to lower combustion temperatures and reduce nitrogen oxide (NOx) emissions; the computer has determined the actual flow is below what it commanded. The most common reason is carbon buildup clogging the EGR valve or its passages. You may notice pinging/knocking, rough idle, or a check engine light, and the car will fail emissions testing. Typical repair costs on Ford range from $300 to $5,000, depending on the specific model and root cause.
Common Causes of P0401
- •Carbon buildup clogging the EGR valve or passages
- •Stuck or faulty EGR valve
- •Blocked or restricted EGR ports/tubes
- •Faulty EGR temperature or position sensor
- •Faulty DPFE/EGR pressure sensor (on applicable systems)
- •Vacuum leak or failed vacuum control (vacuum-operated EGR)
- •Wiring or connector problems at the EGR valve
P0401 on Ford by Model
Ford Explorer(1 issue)
- 360-Degree / Rearview Camera System Failure2020-2024
A software failure in the 360-degree camera system's image processing module can cause the rearview camera to display a blank/black image when the vehicle is placed in reverse, or the image may remain frozen on the display after the backing event has ended. This affects driver visibility and increases the risk of backing collisions.
Ford F-150(1 issue)
- Driveshaft Carrier Bearing Failure2015-2020
The two-piece driveshaft uses a center support (carrier) bearing that can wear out, causing vibration and noise. The rubber support degrades over time, especially in hot climates or with heavy towing. Ford TSB addresses this issue.
Ford F-250 Super Duty(2 issues)
- 6.7L Power Stroke EGR Cooler Clogging and Failure2011-2019
The EGR (Exhaust Gas Recirculation) cooler on 2011-2019 6.7L Power Stroke diesel engines is prone to clogging with soot and eventually failing, particularly on trucks used for highway driving, light loads, or trucks that idle extensively. The EGR cooler recirculates cooled exhaust gas back into the intake to reduce NOx emissions. Over time, soot accumulates in the cooler's internal passages until coolant flow is restricted, causing the cooler to overheat and fail. When it fails, exhaust gases enter the coolant system, causing overheating and "puking" coolant from the degas bottle. The 2011-2014 models are particularly susceptible due to narrow internal coolant passages. Ford issued TSBs for 2011-2014 trucks covering EGR cooler cleaning/replacement under extended warranty up to 120,000 miles. The EGR cooler for 2011-2016 is OEM part BC3Z-9V425-A; 2017+ is HC3Z-9V425.
- 6.0L Powerstroke EGR Cooler Rupture and Coolant Leak2003-2007
The 6.0L Powerstroke diesel in 2003-2007 F-250s is infamous for EGR cooler failure. The cooler develops internal cracks that allow exhaust gas to enter the cooling system and coolant to enter the exhaust. This produces white smoke from the exhaust, coolant loss, and can cause hydrolocking if coolant enters the cylinders. The EGR cooler failure is often caused by clogged oil coolers that prevent proper coolant flow. This is arguably the most well-known diesel engine defect in Ford history.
Ford Maverick(1 issue)
- 12V Battery Drain and Loss of Drive Power - Recall 24S24 + SSM 530872022-2024
Ford Maverick trucks from 2022-2024 are affected by multiple 12V battery-related issues. Ford Safety Recall 24S24 (NHTSA 24V267) covers the BCM/PCM software inability to detect declining 12V battery performance, leading to Auto Start-Stop failures and vehicle stalling at low speeds. Additionally, Ford issued SSM (Special Service Message) 53087 for select 2022-2024 Maverick hybrids where the 12V battery drains intermittently when the ignition is turned off. MaverickTruckClub.com documents owners receiving "Remote Access disabled to reserve battery" FordPass alerts, with some needing 3+ battery replacements in 2-3 years. The hybrid system's complex 12V management appears to be the root cause of accelerated battery degradation.
Looking for P0401 on a different make?
View P0401 across all makes →Frequently Asked Questions
What does P0401 mean on Ford?▼
P0401 stands for "Exhaust Gas Recirculation Flow Insufficient." This code means the Exhaust Gas Recirculation (EGR) system is not flowing enough exhaust back into the engine. The EGR system recirculates a small amount of exhaust into the intake to lower combustion temperatures and reduce nitrogen oxide (NOx) emissions; the computer has determined the actual flow is below what it commanded. The most common reason is carbon buildup clogging the EGR valve or its passages. You may notice pinging/knocking, rough idle, or a check engine light, and the car will fail emissions testing. On Ford specifically, this code is documented across 4 models.
What causes P0401 on Ford vehicles?▼
Common causes on Ford: Carbon buildup clogging the EGR valve or passages, Stuck or faulty EGR valve, Blocked or restricted EGR ports/tubes, Faulty EGR temperature or position sensor, Faulty DPFE/EGR pressure sensor (on applicable systems). Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0401 on a Ford?▼
Repair costs on Ford range from $300 to $5,000, depending on the specific model and root cause.
Which Ford models have P0401 documented?▼
Au7o has documented P0401 on 4 Ford models: Explorer, F-150, F-250 Super Duty, Maverick.