Ask Andy AIP0457 Evaporative Emission System Leak Detected (Fuel Cap Loose/Off)
What it means, what causes it, and what it costs to fix.
What P0457 means
The computer saw a large EVAP leak right after you refueled, so it suspects the gas cap is loose or missing.
Can I drive with P0457?
Severity: Low. Not urgent. Fix it when convenient.
Safe to drive. Tighten the cap and the light should clear on its own after several drives.
Get a diagnosis for your exact car
Tell Andy your year, make, model, and symptoms. You'll get best case, most likely, and worst case, with parts and labor costs. Free, in about 15 seconds.
Ask Andy about P0457Symptoms
- Check engine light or a 'check fuel cap' message
- Fuel smell
Common causes
Most likely first.
- Gas cap not tightened after fueling
- Worn cap seal
- Wrong aftermarket cap
- Damaged filler neck sealing surface
How to diagnose P0457
- Remove the cap, check the rubber seal for cracks, and reinstall it until it clicks.
- If the light doesn't clear after a few days of driving, replace the cap with an OEM one.
Tip: most US auto parts stores will read your codes for free.
Repair costs
| Tighten cap | Free |
| New gas cap | $15–$40 |
Typical US prices. Your vehicle, region, and shop rates will change these.
P0457 FAQ
What does P0457 mean?
P0457 means "Evaporative Emission System Leak Detected (Fuel Cap Loose/Off)." The computer saw a large EVAP leak right after you refueled, so it suspects the gas cap is loose or missing.
Can I drive with a P0457 code?
Safe to drive. Tighten the cap and the light should clear on its own after several drives.
What is the most common cause of P0457?
The most common cause is: Gas cap not tightened after fueling. Other causes include worn cap seal and wrong aftermarket cap.
How much does it cost to fix P0457?
Typical repairs run about $15 to $40 in the US, depending on the cause. Tighten cap: Free.
Still not sure what's wrong?
Describe the noise, smell, or warning light, or snap a photo. Andy is free to try.
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