OBD-II code · Emissions / Engine
The EVAP system is losing a small amount of fuel vapor. A loose gas cap is genuinely the #1 cause. After that: a filler-neck seal, a drying-out purge valve, or a hairline hose.
Charge a diagnostic fee to find the leak, then replace the entire EVAP canister ($600–$900) because it is easier than tracing a 2 mm hose crack.
Typical guess-and-swap cost: $600–$900 (canister) for what was often a $20 part
Tighten the cap and clear the code first (free). Still back? A smoke test pinpoints the exact leak in minutes. Most small leaks are hoses, seals, and valves under $100 in parts.
Mobile service in Canyon Lake, San Antonio & Austin. Written report with root cause — see a sample.