Peugeot P0100

MAF circuit malfunction on Peugeot 1.6/2.0 HDi and 1.6 THP — MAF contamination from EGR and oily breather very common.

Peugeot P0100 — MAF circuit malfunction on Peugeot 1.6/2.0 HDi and 1.6 THP — MAF contamination from EGR and oily breather very common. Typical UK independent garage cost: £100–£320.

What actually causes P0100 on a Peugeot

PSA 1.6 HDi shares MAF failure pattern with Ford TDCi — same engine family. By 90k miles the MAF is contaminated, ECU sees the drifted reading, P0100 stores. 2.0 HDi DW10 similar but slightly more durable. 1.6 THP Prince engine MAF fails by 80k miles, often paired with timing chain stretch P0011/P0014 codes.

Peugeot engines that log P0100

• 1.6 HDi DV6 (208, 308, 3008, Partner)
• 2.0 HDi DW10 (407, 508, 3008, Expert)
• 1.6 THP (208 GTi, 308, RCZ)

How we diagnose P0100 on a Peugeot

1. Lexia / Diagbox — read MAF g/s live
2. Inspect MAF for oil contamination
3. Check breather/oil separator condition
4. Smoke-test intake for leaks
5. Replace MAF and breather together if oily

The common misdiagnosis to avoid

On PSA 1.6 HDi, always inspect the breather/separator AND replace the MAF at the same time — fitting a new MAF over an oily breather contaminates the new one within weeks.

Peugeot P0100 repair cost in the UK

Expect £100–£320 including parts and labour at an independent garage. Main-dealer quotes on Peugeot 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

If a customer with a 1.6 HDi brings P0100 and the engine breather catch can is full of oil, replace breather + MAF + air filter in one go — saves them coming back in 8 weeks with the same fault.

Codes usually seen alongside P0100 on Peugeot

• P0101
• P0102
• P0299
• P0401

Symptoms drivers report with P0100

• Black smoke on diesel acceleration (over-fuelling because ECU can't trust the airflow reading)
• Rough or 'hunting' idle at traffic lights — RPM wanders between 700 and 950
• Hesitation off the mark, then a sudden shove of power as the ECU falls back to a default air-map
• MPG drops 5–10 in mixed driving — the ECU can't run closed-loop trims without valid MAF data
• Engine surges at steady 50–60 mph motorway cruise
• Sometimes resets itself after key-off / key-on and drives normally for a day
• Often stored alongside P0101 (range) or P0102 (low input) — same root cause

Repairs that clear P0100

• Clean MAF with dedicated cleaner spray
• Replace MAF sensor
• Inspect wiring and connector
• Replace air filter

For the generic, all-makes explanation of this code — meaning, every known cause and UK cost bands — see our P0100 guide.

Reading P0100 on a Peugeot properly

A generic reader will show P0100 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 Peugeot 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 P0100 without fixing it

Erasing the code resets the Peugeot'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 P0100 is showing on your Peugeot, 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.