P0456 on Your 2024 Acura TLX
A P0456 code on your 2024 Acura TLX means the PCM found a very small leak (0.020-inch equivalent) in the EVAP system. Your TLX—available with the 2.0L turbo I4 or the Type S's 3.0L turbo V6—uses Honda/Acura's EVAP monitoring with a canister vent shut valve. On a new model, this is typically minor and fully covered by warranty.
Likely Causes
- Gas cap not fully seated (35%) — The simplest explanation. Click it firmly.
- Software calibration sensitivity (22%) — PCM updates may adjust EVAP thresholds.
- Factory EVAP connection variance (18%) — A fitting not fully engaged.
- Canister vent shut valve or purge valve (13%) — A component slightly out of spec.
- New seal break-in (7%) — Fresh seals needing cycling.
- Transport artifact (5%) — A connection disturbed during delivery.
What to Do
- Check the gas cap — Remove, inspect, reinstall with a click.
- Acura dealer visit — Full warranty, zero cost.
- Software update and physical repair — Dealer handles everything.
Cost
- Under warranty: $0—covered through 2028 (basic) and 2032 (emissions)
- Gas cap (DIY): $15–$30
Warranty
Your 2024 TLX carries Acura's 4-year/50,000-mile basic warranty through 2028 and federal emissions coverage for 8 years/80,000 miles through 2032. Let the dealer handle it.