Check Engine Code
P0440
Evaporative Emission Control System Malfunction
Severity: low
DIY difficulty: 1/5
Typical cost: $0–$400
What P0440 means
The EVAP system captures fuel vapors from the tank and feeds them to the engine instead of venting them. P0440 is a generic 'something in EVAP is wrong' code; it's often set alongside more specific codes like P0442 or P0455.
Symptoms
- Check engine light
- Slight fuel smell (rare)
- No drivability issue
Likely causes (most common first)
- Loose or cracked fuel cap (free fix — check here first)
- Cracked EVAP hose
- Failed EVAP purge or vent valve
- Cracked charcoal canister
Can I keep driving?
Low — mostly emissions/economy
Typical repair cost
DIY fixes can start near $0 (parts only). Shop repairs for P0440 typically run up to $400 depending on the underlying cause and vehicle. Start with the most common cause — Loose or cracked fuel cap (free fix — check here first) — before throwing parts at it.
Related codes
Confirm P0440 yourself in 60 seconds
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