Error code
OBD2 P0456
OBD2P0456
Diagnostic Trouble Code· Standard OBD-II fault code read from the vehicle's onboard diagnostics.
What it means
Evaporative Emission System Leak Detected (very small leak).
Severity
moderateCan drive, but should address the issue to prevent further problems.
Summary
P0456 indicates a very small leak in the evaporative emissions (EVAP) system, which is part of the vehicle's fuel vapor management system.
Symptoms
- No noticeable symptoms other than an illuminated MIL
Common Causes
- Loose or defective fuel cap
- Damaged EVAP hoses/lines
- Faulty EVAP pressure sensor
- Cracked or broken charcoal canister
Diagnosis
- Inspect and replace fuel cap if necessary.
- Check EVAP system hoses for damage.
- Test EVAP pressure sensor.
- Smoke test EVAP system for leaks.
Fixes
- Replace the fuel cap or repair damaged hoses/lines.
FAQ
What should I do if my MIL is on and P0456 is set?
Start by checking your fuel cap. If it's loose, defective, or missing, replace it. Then inspect the EVAP system hoses for any damage.
Not affiliated with OBD2. Answer summarized from the manufacturer's manual linked above; consult that source for the authoritative procedure.
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- P0404Exhaust Gas Recirculation Control Circuit Range/Performance
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