What Honda codes (P0420, P0011, P0171, P0299, P0016, P0455) actually mean on Honda engines — the real cause, the common misdiagnosis, and the honest UK repair cost.
These are the OBD fault codes we see most often on Honda vehicles in the workshop, with the real cause on Honda engines rather than the generic textbook definition, plus the honest independent-garage cost.
Honda fault codes explained
- P0420 — Catalyst efficiency on Honda — Civic and Jazz cats are a major UK theft target, especially the IMA hybrid variants. Typical UK cost £280–£1200.
- P0011 — VTC actuator fault on Honda K-series and R-series — the cam phaser rattles on cold start and the ECU logs P0011 once advance error exceeds threshold. Typical UK cost £280–£850.
- P0171 — System too lean on Honda — intake manifold gasket, PCV valve and dirty MAF are the headline causes. Typical UK cost £50–£600.
- P0299 — Turbo underboost on Honda 1.5/1.0 VTEC Turbo and 1.6 i-DTEC — charge pipe splits and intercooler condensation. Typical UK cost £160–£950.
- P0016 — Crank/cam correlation Bank 1 on Honda — VTC actuator on K20/K24 and 1.5T VTEC Turbo chain. Typical UK cost £280–£1200.
- P0455 — EVAP gross leak on Honda — fuel cap and well-known charcoal canister vent valve on Civic/Jazz. Typical UK cost £25–£320.
- P0341 — Camshaft position sensor performance on Honda — K20/K24 CMP sensor and VTC actuator overlap symptoms. Typical UK cost £140–£380.
Codes are generic across manufacturers, but the fix is not. The same code on a Honda 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.