What does P0457 mean?
The computer saw a sudden large EVAP leak right after refueling, which usually means the fuel cap was not put back on or is not sealing.
Codes are a starting point. They tell you which test failed, not which part to replace. Check for other stored codes and fix those in a sensible order.
Symptoms
- Check engine light
- Possible fuel smell
- Hard starting after refueling (with purge problems)
- No change in how the car drives in most cases
Common causes
- Fuel cap loose or missing
- Damaged cap seal
- Wrong aftermarket cap
How to diagnose P0457
- Check and tighten the cap until it clicks.
- Inspect the seal and the filler neck rim.
- If it comes back, have a smoke test done.
How to fix it
- Tighten or replace the fuel cap
Estimated repair cost
Likely repairs for P0457 run from about $15 to $200, depending on the cause.
| Repair | Typical range (parts + labor) |
|---|---|
| Fuel cap replacement | $15 - $45 |
| EVAP smoke test | $100 - $200 |
These are rough US estimates for an independent shop in 2026, based on typical parts prices and standard labor times. Dealers, big trucks, luxury brands and high-cost areas often run higher. They are not quotes. Use the repair cost estimator to adjust for your vehicle.
How serious is P0457?
Low severity
Safe to drive. It will fail an emissions test until fixed.
P0457 FAQ
What does P0457 mean?
P0457 stands for "Evaporative Emission System Leak Detected (Fuel Cap Loose/Off)". The computer saw a sudden large EVAP leak right after refueling, which usually means the fuel cap was not put back on or is not sealing.
Can I drive with a P0457 code?
Safe to drive. It will fail an emissions test until fixed.
How much does it cost to fix P0457?
It depends on the cause. The likely repairs for P0457 range from about $15 to $200 at an independent shop in the US, plus a diagnostic fee of roughly $100-$200. These are rough estimates; dealer prices and some vehicles run higher.
What is the most common cause of P0457?
The most common causes are: fuel cap loose or missing; damaged cap seal; wrong aftermarket cap.