p0401
Moderate
Ford · Trucks
Exhaust Gas Recirculation (EGR) Flow Insufficient
Quick Answer
Error code P0401 on your Ford Trucks means: Exhaust Gas Recirculation (EGR) Flow Insufficient. This is usually fixable — see the step-by-step guide below.
Affected Models
Likely Causes
  1. Carbon buildup blocking EGR passages
  2. Faulty EGR valve stuck closed
  3. Clogged EGR tube or port in intake manifold
  4. Faulty DPFE (Differential Pressure Feedback EGR) sensor
  5. Damaged EGR vacuum hose or solenoid
How to Fix It
1
Inspect EGR valve for carbon buildup and clean or replace
2
Check DPFE sensor hoses for cracks or blockages
3
Test DPFE sensor voltage readings with a multimeter
4
Clean EGR passages in the intake manifold
5
Verify EGR vacuum solenoid operation
Pro Tip
This fix requires some technical knowledge. If you're unsure about any step, consider contacting support or a qualified technician.
Parts You May Need
EGR valve
DPFE sensor
EGR vacuum solenoid
EGR gasket
Related Error Codes
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