Fuel smell and EVAP codes are the same story: vapor is escaping somewhere. Find it before you buy it.

What it usually proves to be (in order)

1. 1Loose, missing, or worn gas cap — genuinely the number-one cause
2. 2A dried-out filler-neck seal or a cracked EVAP hose (a $20 part)
3. 3A purge valve stuck open — click test, then replace for under $100
4. 4A genuinely failed canister — real, but the last item on the list, not the first

What a parts-changer will tell you

Charge a diagnostic fee, then quote the whole EVAP canister assembly ($600–$900) because swapping a canister is easier than tracing a 2 mm hose crack.

Typical guess-and-swap cost: $600–$900 (canister) for what is usually a sub-$100 cap, seal, valve, or hose

The test that proves it

Tighten-the-cap first (free). Still back? A smoke test lights up the exact leak point — including the ones only visible at fuel-pump time.