Is it safe to drive with a P0440 code?

Severity is low. Address P0440 sooner rather than later — driving with an active check engine light can worsen the problem or void emissions warranties.

How much does it cost to fix P0440?

Repair costs for P0440 typically range from $0 to $400 in the US, depending on the underlying cause. The most common fix is: Loose or cracked fuel cap (free fix — check here first).

What are the symptoms of P0440?

Check engine light. Slight fuel smell (rare). No drivability issue.

Check Engine Code

P0440

Evaporative Emission Control System Malfunction

Severity: low DIY difficulty: 1/5 Typical cost: $0–$400

Last updated April 30, 2026

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.