P0456 Evaporative Emission Control System Leak Detected (Very Small Leak)

P0456 indicates a very small leak in the EVAP system. The leak can be tiny enough that visual inspection alone may not find it.

Code status

Needs verification

Not yet verified against SAE J2012_202509 / J2012DA. Treat unverified rows as a lookup aid, not repair authority.

System
Emissions
Scope
iso-sae-controlled-p0
Standard
SAE J2012 / ISO 15031-6
Source
legacy-import

Diagnostic boundary

A diagnostic trouble code reports that a monitored test failed. It does not prove one specific part is bad, and manufacturer logic can add vehicle-specific conditions.

Do not assume a very small leak is harmless; it can keep readiness monitors incomplete and may require precise leak testing.

Useful checks before replacing parts

Related OBD-II codes

These nearby emissions entries can help compare wording and fault area. They may share the same verification status as the source database.