P0456 on Your 2024 Audi A6
A P0456 code on your 2024 Audi A6 indicates the ECM has found a very small leak (0.020-inch equivalent) in the EVAP system. Your A6 uses the VW Group's LDP and N80 EVAP architecture. On a new model, this is typically minor and fully covered by Audi's comprehensive warranty.
Likely Causes
- Gas cap not fully seated (33%) — Most common cause. Tighten firmly.
- Software calibration sensitivity (22%) — ECM updates may adjust thresholds.
- Factory EVAP connection variance (18%) — A fitting not fully engaged.
- N80 purge valve irregularity (15%) — A marginal component.
- LDP variance (7%) — A marginal reading.
- New seal break-in (5%) — Fresh seals needing cycling.
What to Do
- Check the gas cap — Remove, inspect, reinstall.
- Audi dealer visit — Full warranty, ODIS diagnostics, TSB check. Zero cost.
- Software update and repair — Dealer handles everything.
Cost
- Under warranty: $0—covered through 2028 (basic) and 2032 (emissions)
- Gas cap (DIY): $15–$40
Warranty
Your 2024 A6 carries Audi'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.