P0456 on Your 2024 Lincoln Navigator
A P0456 code on your 2024 Lincoln Navigator signals the PCM has found a very small leak (0.020-inch equivalent) in the EVAP system. On Lincoln's flagship full-size luxury SUV with the 3.5L twin-turbo V6, this code is typically minor and fully warranty-covered.
Likely Causes
- Gas cap not fully seated (33%) — The most common trigger. Ensure it clicks firmly.
- Software calibration sensitivity (22%) — Ford/Lincoln may have PCM calibration updates adjusting EVAP thresholds.
- Factory EVAP connection variance (18%) — A fitting not 100% engaged from assembly.
- Purge or vent valve irregularity (14%) — A component slightly out of spec.
- New seal break-in (8%) — Fresh seals needing thermal cycling.
- Transport artifact (5%) — Connection disturbed during delivery.
What to Do
- Check the gas cap — Remove, inspect, reinstall firmly.
- Lincoln dealer visit — Full warranty, zero cost. FDRS diagnostics and TSB check.
- Software update and repair — Dealer handles everything under warranty.
Cost
- Under warranty: $0—covered under Lincoln's 4-year/50,000-mile warranty through 2028
- Gas cap (DIY): $15–$35
Warranty
Your 2024 Navigator carries Lincoln's 4-year/50,000-mile comprehensive warranty through 2028, the 6-year/70,000-mile powertrain warranty through 2030, and federal emissions coverage for 8 years/80,000 miles through 2032. Let the dealer handle it.