What does this code mean?
P0442 describes a small leak, P0455 a large leak and P0456 a very small leak. Check the correct fuel-cap seal where fitted, hoses, valves and the manufacturer's leak-test procedure. A loose cap is one possibility, not the only cause. Do not use compressed air or improvised flame tests around fuel vapour.
Sources and interpretation [1]
A code identifies a detected condition, not a part that must automatically be replaced.
Manufacturer communications
5Original wording in English
INFINITI
Reported code forms P0455
EVAP LEAK DTC P0442, P0455, P0456 INFORMATION This bulletin has been amended. See AMENDMENT HISTORY on the last page. Please discard previous versions of this bulletin.
INFINITI
Reported code forms P0455
ALL MODEL YEAR 2012 AND NEWER INFINITI VEHICLES; EVAP LEAK DTC P0442, P0455, P0456 INFORMATION This bulletin has been amended. See Amendment History on the last page. Please discard previous versions of this bulletin.
INFINITI
Reported code forms P0455
ALL MODEL YEAR 2012 AND NEWER INFINITI VEHICLES; EVAP LEAK DTC P0442, P0455, P0456 INFORMATION This bulletin has been amended. The publication date has been revised to include the latest models and model years, and the…
INFINITI
Reported code forms P0455
SERVICE INFORMATION If one or more of these EVAP leak DTCs are stored (P0442, P0455, P0456) on a 2007 through 2011 Infiniti vehicle, a loose fuel fill cap may be the cause. Use the following resources to perform…
INFINITI
Reported code forms P0455
INFINITI: DUE TO A LOOSE FUEL FILL CAP, THE EVAP LEAK DTCS (P0442, P0455, P0456) ARE STORED AND MAY BE THE CAUSE. MODEL YEARS 2007-2011. NO MODELS LISTED. *PE
Check vehicle applicability
7A listed vehicle is a research lead. Confirm the engine, production range and software in the manufacturer's information.
Before replacing a part
Record codes and freeze-frame data. Check battery condition, related codes and visible wiring or hose damage. Follow the vehicle's diagnostic procedure and test results before replacing parts.
Sources and interpretation
These explanations are editorial summaries of the linked manufacturer material. PDF page numbers count from the first file page. Original publications are in English; translations are reference aids. A cited edition is not a claim that it is the manufacturer's latest instruction.
- 2024–2025 MY OBD System Operation Summary for Gasoline Engines ↗
Ford Motor Company · PDF page(s) 11, 12 ·
Source check date · 2026-10-27
Can I keep driving?
A code alone cannot establish whether driving is safe. A flashing malfunction light, severe shaking, overheating, oil-pressure warning or loss of braking or steering needs prompt attention. Stop in a safe place and seek assistance when control or engine safety is affected. Follow the vehicle handbook.