DPFESensor

EGR Differential Pressure Feedback Sensor (DPFE)

Group: Emissions and exhaust

The DPFE sensor measures how much exhaust gas recirculates through the EGR valve by comparing the pressure before and after a calibrated orifice. It is typical of Ford and Mazda, and when it fails it sets P0401 and P1401.

Contents

What does the DPFE sensor do?

Two hoses bring the exhaust pressure on each side of a calibrated orifice in the EGR tube to the sensor. The bigger the pressure difference, the more gas is recirculating. The computer uses this value to confirm that the EGR valve opens as far as it was commanded. If the difference is smaller than expected, it logs insufficient EGR flow.

Where is it located?

In the engine bay, mounted on the body or the engine, with two rubber hoses connected to the EGR tube.

Signal type and reference values

  • 3 wires: 5 V, ground and signal.
  • No EGR flow (idle): about 0.45 to 1.0 V depending on the model.
  • With the EGR open: the signal rises toward 2 to 4 V.

Values are a guide only: always check the manufacturer's data for your engine.

Symptoms of a bad DPFE sensor

  • Check engine light with P0401 or P1401.
  • Pinging on acceleration if no exhaust gas is recirculated.
  • Rough idle if the reading makes the EGR open at idle.
  • In many cases there are no driveability symptoms.

How to test the DPFE sensor step by step

  1. Check both hoses: they crack, melt or clog with soot. This is the most common cause.
  2. Make sure the hoses are on the correct ports (high and low pressure).
  3. At idle the signal should sit at its rest value; when you open the EGR with the scan tool or a vacuum pump, it should rise.
  4. Clean the calibrated orifice and the EGR tubes if they are clogged.
  5. Check 5 V and ground at the connector.

Trouble codes related to the DPFE sensor

Frequently asked questions about the DPFE sensor

Is the DPFE the same as the EGR valve?
No. The EGR valve opens the passage for the exhaust gas; the DPFE measures how much gas actually flows.
Why do DPFE sensors fail so often?
Because they receive hot, sooty exhaust gas. The plastic versions suffer from the heat, and many manufacturers replaced them with metal versions.

Updated September 25, 2026. Values are a guide only: always confirm them in the service manual for your engine.

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