What Peugeot codes (P0234, P0420, P0401, P0203, P0106, P0100) actually mean on Peugeot engines — the real cause, the common misdiagnosis, and the honest UK repair cost.
These are the OBD fault codes we see most often on Peugeot vehicles in the workshop, with the real cause on Peugeot engines rather than the generic textbook definition, plus the honest independent-garage cost.
Peugeot fault codes explained
- P0234 — Turbo overboost on Peugeot 1.6 / 2.0 HDi — usually the wastegate actuator or VGT sticking from carbon, not the turbo itself. Typical UK cost £180–£1400.
- P0420 — Catalyst efficiency on Peugeot petrol — 1.2 PureTech and older 1.6 VTi often have lambda drift before genuine cat failure. Typical UK cost £140–£750.
- P0401 — EGR flow insufficient on Peugeot 1.6/2.0 HDi (PSA DV6/DW10) diesels — sticking EGR valve or clogged FAP/DPF causing back-pressure. Typical UK cost £180–£720.
- P0203 — Injector circuit Cylinder 3 on Peugeot 1.6/2.0 HDi — Siemens/Continental piezo injectors fail with age, plus chronic injector seal blow-by. Typical UK cost £220–£780.
- P0106 — MAP sensor performance on Peugeot 1.6 THP/1.6 HDi — shared PSA/BMW Prince engine MAP failure and HDi charge-pipe splits. Typical UK cost £100–£380.
- 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 cost £100–£320.
- P244A — DPF differential pressure too low on Peugeot HDi — Eolys additive system & pressure pipes are the usual culprits. Typical UK cost £160–£1600.
- P0299 — Turbo underboost on Peugeot HDi and PureTech — VGT actuator carbon-up on diesels, wastegate solenoid on PureTech petrol. Typical UK cost £160–£1500.
- P0171 — System too lean on Peugeot — PSA THP and PureTech engines have known PCV and intake gasket weaknesses. Typical UK cost £180–£700.
- P0016 — Crank/cam correlation Bank 1 on Peugeot — 1.6 THP Prince engine timing chain stretch (208 GTi, 308, RCZ). Typical UK cost £600–£2400.
- P2002 — DPF efficiency below threshold on Peugeot HDi — clogged DPF and Eolys fluid empty on 1.6/2.0 HDi. Typical UK cost £140–£1400.
- P0341 — Camshaft position sensor performance on Peugeot — 1.6 HDi DV6 sensor degrades with engine heat. Typical UK cost £65–£280.
- P0011 — VVT 'A' over-advanced Bank 1 on Peugeot — 1.6 THP Prince VVT solenoid and chain stretch (208 GTi/308/RCZ). Typical UK cost £60–£2400.
- P0087 — Fuel rail pressure too low on Peugeot — 1.6/2.0 HDi lift pump and Bosch DRV failure. Typical UK cost £180–£1400.
- P2463 — DPF soot accumulation on Peugeot HDi — Eolys-additive system failure and over-soot. Typical UK cost £140–£1400.
- P0118 — Coolant temperature sensor high input on Peugeot — very often the sensor itself on PSA engines, with corroded plugs close behind. Typical UK cost £35–£220.
Codes are generic across manufacturers, but the fix is not. The same code on a Peugeot usually points at a different component than it would on another make, which is why a make-specific diagnosis saves money before any parts are bought.
Reading codes properly on a Peugeot
A £20 reader pulls generic engine codes and nothing else. On a Peugeot the useful information often sits in the gearbox, ABS, body or comfort modules, and those need a tool that talks the manufacturer protocols. Just as important is the freeze-frame data stored with the code: engine speed, load, coolant temperature and fuel trims at the exact moment the fault was logged. That snapshot is usually what separates a failing sensor from a real mechanical problem, and it is the first thing we look at before anything is unbolted.
Why the same code costs different money on a Peugeot
Each code on this page has a cost range rather than a price because the cheap cause and the expensive cause log identically. A split hose and a failed turbo can both set a boost code. Access matters too — some Peugeot engines put the awkward part behind half the front end, and the labour, not the part, is what moves the bill. An honest quote names which cause has been confirmed and what the repair for that specific cause costs.
Getting a Peugeot fault diagnosed
Bob's Mechanical Repairs is an independent, family-run garage in Birnam, Dunkeld, Perthshire, a couple of minutes off the A9. Bob has 32 years on the tools, and diagnostics are charged as diagnostic time with the findings explained in plain English and the repair priced before any work is agreed. An MOT is £54.85 if the car is due one at the same time.
Common questions
How do I read fault codes on a Peugeot? Any generic OBD-II reader will pull engine codes from a Peugeot built after 2001, but manufacturer-level codes from the gearbox, ABS and body modules need a tool that speaks the Peugeot protocols. That is why a garage scan often finds codes a cheap reader misses.
Will clearing a Peugeot fault code fix it? No. Clearing the code only erases the record. If the fault is still present it returns on the next drive cycle, and in the meantime the readiness monitors are reset, which can stop the car passing an emissions check.
How much is a Peugeot diagnostic at an independent garage? An hour of diagnostic time is typically £50–£90 in the UK, against £110–£180 at a main dealer. It almost always costs less than the part it stops you buying by mistake.