Evaporative emissions system leak detected, small leak

A small-leak monitor result for the fuel-vapor system, not a location for the leak.

WHAT IT GENERALLY REPORTS

A starting point, not a parts list.

The evaporative-emissions monitor detected a leak within the small-leak range it is designed to identify. The code does not locate the leak or confirm which seal, line, or component is involved.

Common symptoms

The check-engine light is common; other symptoms may be absent.
A fuel-vapor odor may be noticed in some cases.
The code may appear after a refueling event, though timing alone does not prove the cause.

Possible causes

A fuel cap that is missing, not seated, or has a worn seal on vehicles equipped with a removable cap.
A leak or sealing issue elsewhere in the evaporative-emissions system.
A valve or monitoring issue that needs vehicle-specific testing to distinguish from a leak.

Safe initial checks

If the vehicle has a removable fuel cap, check that it is present and appears seated; do not force it.
Record the exact code and note whether it appeared after refueling.
If you smell fuel strongly or see a spill, avoid ignition sources, move away, and seek appropriate assistance.

When to get professional help

Have a technician test the evaporative-emissions system if the code returns or the fuel odor persists.
Capless fuel systems and vehicle-specific leak tests differ; do not open fuel lines or emissions components based on a generic guide.