The two rubber hoses on the DPFE sensor are physically swapped, which is the most common cause.; Hoses are cracked, split, or disconnected, causing a pressure signal that mimics reversal.; The DPFE sensor itself is faulty and misinterprets the pressure differential.; The EGR tube or passage is clogged with carbon, altering the pressure relationship between the two ports.; Wiring to the DPFE sensor is damaged or corroded, leading to an erratic signal that the PCM interprets as reversed hoses.; The PCM has a calibration issue or has not been updated with the latest software for the DPFE sensor strategy.

DTC codes / Ford codes / P1403

P1403 · FordDifferential Pressure Feedback Electronic Sensor Hoses Reversed

P1403 on Ford vehicles indicates that the differential pressure feedback electronic (DPFE) sensor has detected a reversed hose connection, meaning the two pressure hoses that connect the sensor to the exhaust gas recirculation (EGR) tube are swapped. The powertrain control module (PCM) compares the pressure signal from the DPFE sensor to expected values and sets this code when the signal indicates the hoses are reversed, which causes the EGR flow calculation to be incorrect.

SystemPowertrain

Code typeFord specific

SeverityLow

Fix difficultyIntermediate

AreaAuxiliary emission controls

Symptoms you may notice

Illumination of the check engine light, often with no other noticeable symptoms.
Slight rough idle or hesitation during acceleration if the EGR flow is disrupted.
Reduced fuel economy due to incorrect EGR metering.
Intermittent engine ping or knocking under light load if EGR flow is excessive.
Failed emissions test because the EGR monitor will not complete or the system is not ready.
In rare cases, a stored code may be the only sign, with no drivability complaints at all.

Common causes, most likely first

The two rubber hoses on the DPFE sensor are physically swapped, which is the most common cause.
Hoses are cracked, split, or disconnected, causing a pressure signal that mimics reversal.
The DPFE sensor itself is faulty and misinterprets the pressure differential.
The EGR tube or passage is clogged with carbon, altering the pressure relationship between the two ports.
Wiring to the DPFE sensor is damaged or corroded, leading to an erratic signal that the PCM interprets as reversed hoses.
The PCM has a calibration issue or has not been updated with the latest software for the DPFE sensor strategy.

How to diagnose and fix it

Inspect the two hoses at the DPFE sensor and compare their routing to the underhood vacuum diagram or service information; swap them if reversed.
Check the hoses for cracks, splits, or loose connections and replace any damaged hose.
Remove and clean the EGR tube and passages to ensure they are free of carbon buildup.
Test the DPFE sensor with a scan tool and a vacuum pump to verify it produces the correct voltage or frequency for a given pressure differential.
Inspect the DPFE sensor connector and wiring for corrosion, chafing, or loose pins, and repair as needed.
Clear the code and perform a road test to verify the repair, ensuring the EGR monitor runs and passes.
If the code persists after all checks, reprogram the PCM with the latest calibration or replace the DPFE sensor if testing indicates it is faulty.

Before you replace the DPFE sensor

A swapped hose connection is easy to overlook because the hoses often look identical and may have been recently replaced during other repairs.
Carbon blockage in the EGR tube can create a pressure difference that the DPFE sensor interprets as reversed hoses, so cleaning the tube is often necessary even after correcting hose routing.
The DPFE sensor on Ford vehicles is a common failure item, but replacing it without checking hose routing and tube condition will likely lead to a repeat code.
Some aftermarket DPFE sensors have different voltage output curves than the OEM part, which can cause false reversal codes even when the hoses are correctly installed.
A dirty or failing mass airflow (MAF) sensor can skew EGR flow calculations and set related codes, so it is worth checking if the DPFE system appears correct.

Can I keep driving with P1403?

The vehicle is generally safe to drive with P1403 because the EGR system is not critical for engine operation, but you should avoid heavy acceleration or towing until the fault is repaired to prevent potential engine knock or increased emissions. Have the code diagnosed soon to maintain fuel economy and ensure the vehicle passes emissions testing.

Tools that help

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Guidance is general and written for Ford vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.