p0401
Moderate
Ford · SUVs
Exhaust Gas Recirculation (EGR) Flow Insufficient
Quick Answer
Error code P0401 on your Ford SUVs 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 valve or passages
  2. Faulty EGR valve stuck in the closed position
  3. Clogged DPFE sensor hoses
  4. Faulty DPFE sensor providing incorrect feedback
  5. EGR vacuum solenoid failure
How to Fix It
1
Remove and inspect EGR valve for carbon buildup; clean or replace
2
Inspect DPFE sensor hoses for cracks, blockages, or deterioration
3
Test DPFE sensor voltage output with a multimeter
4
Clean EGR passages in the intake manifold if clogged
5
Verify EGR vacuum solenoid opens when commanded
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
DPFE hoses
EGR gasket
Related Error Codes
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