OBD codes / P0456 / Honda CR-V
P0456 on a Honda CR-V
Evaporative Emission System Leak Detected (Very Small Leak)
All modern CR-Vs with EVAP monitoring.
What P0456 usually means on a CR-V
P0456 is the pinhole-leak version of the CR-V's EVAP fault, caught during the sensitive small-leak monitor. The tiny size makes these hard to find without a smoke test. The gas cap O-ring and the canister vent valve seal lead the causes, followed by hairline hose cracks. Diagnosis usually costs more than the parts.
Most likely causes on this model
- Weeping gas cap seal
A slightly worn cap O-ring passes the large-leak test but fails the small-leak monitor.
- Vent valve not sealing fully
A vent valve that will not seat leaks the small volume this code detects.
- Tiny hose or grommet cracks
Age-hardened lines and a dried purge-valve grommet leak just enough.
- Leaking purge valve
A purge valve that will not fully close bleeds vapor.
What it costs on a CR-V
Pay for the smoke test to pinpoint the pinhole rather than guessing. The parts - cap, vent valve, hose - are inexpensive. Budget more for diagnostic time than components on the CR-V.
Year, engine and mileage change the answer. Get a diagnosis for your CR-V — it weighs these causes against your exact configuration and real complaint data.
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Related symptoms
Honda CR-V problems & recalls by year
Based on widely reported patterns for this model; individual causes vary by year, engine and history. Generic P0456 behavior is covered on the main P0456 page. Confirm with a scan tool before buying parts.