2017 Acura P0456: What It Means & Is It Safe to Drive?
P0456 on the 2017 Acura: Evaporative Emission System Leak Detected (Very Small Leak). Here's what it means, what usually causes it, what repairs typically cost, and whether it's safe to keep driving.
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What this code means
The EVAP system has detected a very small leak—often smaller than P0442. Commonly caused by a loose fuel cap or hairline crack in a hose.
Common causes on the 2017 Acura
- Loose or worn gas cap seal
- Hairline crack in EVAP hoses
- Minor leak at purge or vent valve fittings
Symptoms
- Check Engine Light only
- Usually no noticeable driving symptoms
Typical fixes
- Inspect and replace gas cap if seal is hardened or cracked
- Smoke-test EVAP system to locate tiny leaks
- Repair or replace leaking hoses and fittings
Repair cost range
For a 2017 Acura, repairs for P0456 typically fall between $25 and $350, depending on the root cause and labor rates in your area.
Known issues on Acura
Acura P0456 small EVAP leak is almost always the gas cap. OEM Acura/Honda caps are recommended. If the cap is good, the canister purge valve can leak internally—inspect with a scan tool actuation test.
Most commonly affected models
TL 2004–2012MDX 2007–2013RDX 2007–2012