Evaporative emission (EVAP)
P0457 — Evaporative Emission System Leak Detected (Fuel Cap Loose/Off)
The ECU believes that the fuel cap is loose or missing because the EVAP system cannot hold pressure. This is often the simplest EVAP code to fix.
Common causes
- Fuel cap loose or not tightened after refuelling
- Fuel cap missing or damaged
- Worn fuel cap seal
- Damaged filler neck sealing surface
- Wrong type of fuel cap
Symptoms
- Check engine light
- Fuel smell
- No driving symptoms
- Failed emissions test
How to check
- Remove and refit the fuel cap until it clicks
- Inspect the cap's seal for cracks and the filler neck for damage
- Replace the cap if needed
- Clear the code and drive for the monitor to run; if it returns, smoke-test the system
Can you keep driving?
Safe to drive. Tighten or replace the fuel cap and the light usually goes out after a few drive cycles.
Related codes
Frequently asked questions
- What does P0457 mean?
- The ECU detected an EVAP leak that typically points to a loose or missing fuel cap.
- How long until the light goes out after I fix the cap?
- Often within a few drive cycles, or immediately if you clear the code with a scan tool.
General reference information. It does not replace a diagnosis on your own vehicle. The same code can have different causes depending on make, model year and engine; check the manufacturer's documentation or ask a technician with a scan tool.