P1400

Manifold Differential Pressure Sensor Circuit

Car Fault Codes Mitsubishi Emissions & exhaust

Can you still drive? Yes, normally

Who can fix it? Needs a workshop

Typical repair time 30 minutes – 1.5 hours

Typical cost SAR 100 to 800

What it means

This is a Mitsubishi-specific code; the same number can mean something different on other makes. Some Mitsubishi models use a manifold differential pressure sensor to monitor the EGR system, measuring the change in manifold pressure when the computer opens the EGR valve. The code means this sensor's signal voltage is outside the expected range, indicating a fault in the circuit or the sensor.

Models covered: Mitsubishi models with EGR monitoring by manifold differential pressure, mainly around 1996–2004.

Symptoms3

Check engine light on.
Driving is usually not noticeably affected.
The EGR monitor cannot complete, which may cause a failed emissions test.

Possible causes5

A disconnected, cracked or blocked vacuum hose to the sensor.
A loose or corroded connector at the sensor.
A broken or shorted wire in the signal, 5-volt reference or ground circuit.
A faulty sensor.
A faulty ECM (rare).

How to diagnose4

Inspect the vacuum hose to the sensor and confirm it is intact and correctly routed.
Inspect the sensor connector and wiring.
Measure reference, ground and signal voltage at the sensor and compare with the manufacturer specification.
Watch the sensor reading on a scan tool as manifold vacuum changes.

How to fix4

Replace or reconnect the damaged vacuum hose.
Clean the connector and repair the damaged wire.
Replace the sensor if reference and ground are good and the signal is wrong.
Clear the codes and drive until the EGR monitor completes, then confirm the code does not return.

Repair cost

0–500

500–2,000

2,000–5,000

5,000+

In Saudi riyals; the highlighted part is the expected range for this fault.

The cost is low when a vacuum hose or connector is the cause, and rises slightly when the sensor is replaced.

Prices are rough estimates for common cars at independent workshops and vary with the car and the source of the part.
Prices last updated: September 2026

Frequently asked questions

Does this code affect engine performance?

Usually not noticeably, since this sensor is mainly used to monitor the EGR system. But it prevents the emissions self-test from completing, so the check engine light stays on.

Is this the same as the MAP sensor?

It does a similar job, but on these models it is dedicated to EGR monitoring, so fit the part specified for the VIN rather than going by appearance.

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This guide is for information only and does not replace an inspection by a qualified technician. If the fault involves brakes, steering, engine temperature, electrics or refrigerant, do not attempt the repair yourself.

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