Ford P0402

EGR flow excessive on Ford diesel — sticking EGR valve stuck open, carbon-loaded on 1.6/2.0 TDCi.

Ford P0402 — EGR flow excessive on Ford diesel — sticking EGR valve stuck open, carbon-loaded on 1.6/2.0 TDCi. Typical UK independent garage cost: £180–£850.

What actually causes P0402 on a Ford

PSA-shared 1.6 TDCi (DV6): the EGR valve carbons up and physically can't close — MAF sees too much recirculated gas. On 2.0 TDCi Transit we see the EGR cooler crack internally, which flows uncontrolled gas back and looks like an EGR-open fault.

Ford engines that log P0402

• 1.6 TDCi DV6 (Focus, C-Max, Mondeo)
• 2.0 TDCi (Mondeo, S-Max, Galaxy)
• 2.2 TDCi Transit

How we diagnose P0402 on a Ford

1. Live-data EGR duty vs actual flow — commanded 0%, actual >5% = stuck open
2. Remove EGR valve, inspect for carbon lock and cracked seat
3. Inspect EGR cooler for internal crack (pressure test)
4. Clean intake manifold when fitting new valve — mandatory

The common misdiagnosis to avoid

Fitting a new EGR valve without cleaning the intake manifold — the fresh valve chokes on carbon within 5k miles. Also, removing or bypassing the EGR is illegal for road use in the UK and MOT emissions will fail.

Ford P0402 repair cost in the UK

Expect £180–£850 including parts and labour at an independent garage. Main-dealer quotes on Ford are usually higher for the same job, and the spread exists because the cheap cause and the expensive cause throw the same code — pay for the diagnosis before you pay for parts.

Bob's workshop tip

1.6 TDCi DV6 — always Delphi OE EGR valve, and always clean the manifold. Pattern valves fail within a year.

Codes usually seen alongside P0402 on Ford

• P0401
• P0403
• P0404

Symptoms drivers report with P0402

• Rough idle, often shaking the gear lever
• Hesitation off the line
• Stalling at junctions
• Possible black smoke at idle
• Engine warning light + power reduction warning

Repairs that clear P0402

• EGR clean or replace
• Sensor inspection

For the generic, all-makes explanation of this code — meaning, every known cause and UK cost bands — see our P0402 guide.

Reading P0402 on a Ford properly

A generic reader will show P0402 and nothing else. What matters is the freeze-frame data stored with it — engine speed, load, coolant temperature and fuel trims at the moment the fault was logged — plus whether any other module on the Ford has logged something at the same time. Codes rarely arrive alone, and the order they were stored in usually points at which one is the cause and which are the consequences.

Clearing P0402 without fixing it

Erasing the code resets the Ford's readiness monitors as well as the light. The fault returns on the next drive cycle if the cause is still there, and in the meantime the incomplete monitors can stop the car passing an emissions check. After a genuine repair, the car is driven until the relevant monitor completes before it is handed back.

Bob's Mechanical Repairs is an independent garage in Birnam, Dunkeld, Perthshire, with 32 years of Bob's experience on the tools. If P0402 is showing on your Ford, bring any scan results with you — we will read the live data ourselves, confirm which cause it actually is, and price the repair before any work starts.