MajorCommonEngine

Mitsubishi Delica: 4N14 Diesel EGR Valve Carbon Sticking — P0401

4N14 Diesel EGR Valve Carbon Sticking — P0401 is a common engine fault on the Mitsubishi Delica on the 2013 onward cars, and we rate it major. Putting it right costs $420 to $1,100 at New Zealand independent workshop rates. Below is what goes wrong, the symptoms to notice on a test drive, where to look, and what to ask the seller before you hand over any money. It is one of 18 documented faults on the Mitsubishi Delica.

Vehicle: Mitsubishi Delica
Engine: 2.3L
Years: 2013 onward
Fuel: diesel
Gearbox: auto
System: Engine

This page covers the Mitsubishi Delica as a model. Some faults only affect particular engines or build years — enter a plate below to narrow the list to one car.

All Mitsubishi Delica faults18 documented faults on this model

What you are looking at

No photograph available

We do not hold a verified photograph of the EGR valve yet. We would rather show none than show a picture of a different part.

What goes wrong

The 4N14 2.2L turbodiesel uses exhaust gas recirculation to reduce NOx emissions. The EGR valve and its passage accumulate carbon deposits from diesel blow-by, particularly in vehicles operated predominantly on short urban runs where exhaust temperatures remain low. Carbon build-up causes the valve to stick partially open or fail to open fully on command. A stuck-open valve recirculates excessive exhaust gas, diluting the air charge and causing rough idle, hesitation on acceleration, and increased smoke. A stuck-closed valve triggers P0401 (EGR flow insufficient detected) and may cause elevated NOx emissions that fail a vehicle inspection. The issue is accelerated on grey imports used for NZ urban shuttle duty after a prior JDM life of predominantly highway use.

What you would notice

Rough or lumpy idle, especially when cold
Hesitation and reduced power during light-throttle acceleration
P0401 fault code — EGR flow insufficient
Increased visible exhaust smoke on acceleration
Idle speed hunting between 600–900 rpm

How to check it

Where to look. Exhaust gas recirculation valve mounted on the intake manifold, driver's side of the 4N14 engine

Inspect the EGR valve body and inlet manifold port for heavy carbon build-up during a visual check. A live data scan showing EGR valve position vs commanded position will confirm stiction. Request any history of EGR cleaning or replacement. If a workshop inspection is possible: Read OBD codes with a diesel-capable scanner and check specifically for P0401 or EGR-related codes.

Parts involved: EGR valve.

What it costs to put right

$420 to $1,100 at New Zealand independent workshop rates. That is for this job on its own, not for the car.

An estimate, in NZD, for the repair as normally carried out. What a specific car costs depends on which part has failed and what it damaged on the way — treat this as the floor for a negotiation, not a quote.

Ask the seller

“Has the EGR valve ever been cleaned or replaced?”
“Has the vehicle mostly been used for short city trips or longer highway runs?”
“Have there been any check engine lights related to emissions or EGR?”

Now check the Mitsubishi Delica you are actually looking at

Everything above is true of the model, and it is free. What it does not tell you is whether THIS car has been looked after: its odometer history and whether the reading has ever gone backwards, whether there is still money owing on it, whether it has been reported stolen, how many owners it has had and what it is really worth today. That comes from the official records for that plate. Enter the plate for the free details, or get the full history and a market valuation from $13.49.

Not sure what you would be paying for? See what a full KickTyres check includes.

Where this comes from

The failure described above is documented in published sources — owner forums, technical service bulletins, recall notices and workshop write-ups — held in our fault database. The inspection instructions and the cost estimate are KickTyres’ own interpretation of them, and it is a starting point for an inspection rather than a manufacturer statement.

Mitsubishi Delica buyer questions

Is 4n14 diesel egr valve carbon sticking — p0401 serious on a Mitsubishi Delica?

We rate it major and common on the Mitsubishi Delica. The 4N14 2.2L turbodiesel uses exhaust gas recirculation to reduce NOx emissions. The EGR valve and its passage accumulate carbon deposits from diesel blow-by, particularly in vehicles operated predominantly on short urban runs where exhaust temperatures remain low. Carbon build-up causes the valve to stick partially open or fail to open fully on command. A stuck-open valve recirculates excessive exhaust gas, diluting the air charge and causing rough idle, hesitation on acceleration, and increased smoke. A stuck-closed valve triggers P0401 (EGR flow insufficient detected) and may cause elevated NOx emissions that fail a vehicle inspection. The issue is accelerated on grey imports used for NZ urban shuttle duty after a prior JDM life of predominantly highway use.

How much does it cost to fix on a Mitsubishi Delica?

$420 to $1,100 at New Zealand independent workshop rates. That figure is for this job on its own. A car showing the symptoms on this page is usually worth either walking away from or negotiating down by at least the repair figure.

Which Mitsubishi Delica years are affected?

Our research records this fault on the 2013 onward Mitsubishi Delica. Build dates move around, especially on imported cars, so treat the range as the years to look hardest at rather than a guarantee either way. The official records tell you the exact build and first registration date for the car in front of you.