P0456 on a Honda CR-V
P0456 means evaporative Emission System Leak Detected (Very Small Leak). On the CR-V, a few causes come up far more than others.
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 common causes on the CR-V
- 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 P0456 costs to fix 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. Start a case and Redline weighs these causes against what your car shows, then names the check that would settle it.
Other codes on the Honda CR-V
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.
P0456 on your CR-V?
Every problem becomes a Case. Tell Redline what your CR-V is doing: it shows what the evidence supports, what’s still missing, and what to check next, before you approve a repair.
“Inner pad ~1 mm. Outer pad 3 mm.”
Next: check the slide pins move freely before buying parts.