P0456 on Your 2022 Acura TLX
A P0456 code on your 2022 Acura TLX means the PCM has detected a very small leak—about 0.020 inches—in the EVAP system. The second-generation TLX (2021+) uses Honda/Acura's EVAP monitoring system with a canister vent shut valve to verify fuel vapor system integrity.
Your 2022 TLX features either a 2.0L turbocharged four-cylinder or the Type S's 3.0L turbo V6, and both share the same EVAP system design. At three-plus years of age, early-wear EVAP issues are possible alongside simpler causes.
Common Causes
- Gas cap seal wear (33%) — Three years degrades the rubber seal. Check first.
- Canister vent shut valve malfunction (23%) — Honda/Acura's vent control can develop faults with age.
- Purge valve seepage (18%) — Slight internal leak in the purge solenoid.
- EVAP line looseness (14%) — Connections worked loose by vibration and thermal cycling.
- Charcoal canister damage (7%) — Road debris impact.
- Fuel tank seal (5%) — Gasket degradation over time.
Diagnostic Steps
- Gas cap replacement — New OEM cap ($15–$30), clear code, monitor.
- Visual inspection — Check EVAP hoses and connections.
- Smoke test — Professional diagnosis to find the exact leak.
- i-HDS diagnostics — Acura dealer tool for detailed EVAP data.
- Component testing — Test vent shut valve and purge valve individually.
Repair Costs
- Gas cap: $15–$30 (DIY)
- Canister vent shut valve: $170–$360
- Purge valve: $140–$310
- EVAP hose repair: $90–$220
- Charcoal canister: $270–$500
Warranty Coverage
Your 2022 TLX is covered under Acura's 4-year/50,000-mile basic warranty through 2026. The federal emissions warranty extends EVAP coverage to 8 years/80,000 miles through 2030. Contact your dealer to verify eligibility.