P0456 on Your 2023 Tahoe: A Quick Fix
Your 2023 Tahoe (T1XX platform, refreshed) has triggered P0456—a very small EVAP leak. With the 5.3L V8, 6.2L V8, or 3.0L Duramax diesel, GM's EVAP system is shared across all powertrains. At 2–3 years old, warranty should cover this completely.
Symptoms
- Check engine light on
- P0456 stored
- No performance or towing issues
- All SUV features normal
Top Causes
- Gas Cap Seal (High Likelihood): Loose or debris on seal. $0–$15 (warranty covers).
- Vent Valve Solenoid (High Likelihood): GM's common EVAP failure. $0 warranty.
- Purge Solenoid (Medium Likelihood): V8 heat. $0 warranty.
- EVAP Connection (Medium Likelihood): Loosened connection. $0 warranty.
- ECM Software (Low Likelihood): Calibration update. $0 warranty flash.
What to Do
- Reseat the gas cap
- Schedule warranty appointment at Chevy dealer
- Dealer diagnoses and repairs at no cost
Cost
- Under warranty: $0
- Bumper-to-bumper through 2026
- Federal emissions through 2031
Can I Tow?
Yes. P0456 has zero impact on the Tahoe's towing, hauling, 4WD, or any capability.
Warranty
GM's 3yr/36k runs through 2026. Federal emissions (8yr/80k) covers EVAP through 2031. Let the dealer handle it at no cost.