Fault-Code Library · EVAP
P0456: EVAP system very small leak detected
The fuel-vapor system has a very small leak during the ECU's leak test.
Common symptoms
- •Engine warning light
- •Usually no drivability symptom
- •Occasional fuel smell
Likely causes
- •Fuel cap seal wear
- •Tiny EVAP hose crack
- •Purge or vent valve seepage
- •Canister or filler-neck seal leak
First checks
- •Inspect fuel cap and filler neck
- •Smoke-test with correct EVAP equipment
- •Check purge and vent valves for seepage
Important
Very small EVAP leaks are hard to find without smoke testing and patience.
A fault code identifies a detected condition, not a failed part. Confirm manufacturer-specific subcodes and live data.
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