What Hyundai codes (P0011, P0420, P0171, P0299, P0016, P0087) actually mean on Hyundai engines — the real cause, the common misdiagnosis, and the honest UK repair cost.
These are the OBD fault codes we see most often on Hyundai vehicles in the workshop, with the real cause on Hyundai engines rather than the generic textbook definition, plus the honest independent-garage cost.
Hyundai fault codes explained
- P0011 — VVT actuator over-advanced on Hyundai 1.6 GDI / 2.0 GDI — often related to the well-documented Theta II / Gamma engine concerns and oil consumption. Typical UK cost £180–£600.
- P0420 — Catalyst efficiency on Hyundai — on 1.6 GDI petrol (Theta II family) the famous engine bearing failures damage the cat with debris. Typical UK cost £180–£1300.
- P0171 — System lean on Hyundai — Gamma 1.6 GDi intake valve carbon and PCV oil mist. Typical UK cost £20–£550.
- P0299 — Turbo underboost on Hyundai 1.6 CRDi and 1.0/1.4 T-GDi — VGT actuator or charge-pipe split. Typical UK cost £180–£1200.
- P0016 — Crank/cam correlation Bank 1 on Hyundai — Theta II 2.0/2.4 GDi chain wear and Kappa 1.0/1.4 T-GDi OCV. Typical UK cost £180–£2400.
- P0087 — Fuel rail pressure too low on Hyundai — 1.6 CRDi U2 lift pump and HP pump wear. Typical UK cost £180–£1400.
- P0234 — Turbo overboost on Hyundai — 1.6 CRDi VGT actuator stuck and 1.0/1.4 T-GDi wastegate. Typical UK cost £160–£1100.
- P2002 — DPF efficiency below threshold on Hyundai — 1.6/2.0 CRDi U2/R-line DPF clogging on i30/Tucson/Santa Fe. Typical UK cost £180–£2200.
- P0341 — Camshaft position sensor performance on Hyundai — Theta II / Gamma / Kappa CMP sensor. Typical UK cost £100–£400.
Codes are generic across manufacturers, but the fix is not. The same code on a Hyundai 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.