What does code P0440 mean on a Ford and is it safe to drive?
P0440: Evaporative Emission System Control System Malfunction. Here's what it means on your Ford, what usually causes it, what repairs typically cost, and how safe it is to keep driving.
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What this code means
A general fault in the EVAP system—could be a leak, stuck valve, or sensor issue.
Common causes for your Ford
- Gas cap loose or faulty
- Purge or vent valve stuck
- Charcoal canister or hose leak
Symptoms
- Check Engine Light
Typical fixes
- Replace gas cap
- Test purge/vent valves
- Smoke test EVAP system
Repair cost range
For a Ford, repairs for P0440 often fall between $20 and $400, depending on the cause and whether you use OEM or aftermarket parts. Labor rates vary by location.
Known issues on Ford
Ford P0440 on F-150 and Explorer frequently traces to a cracked or loose filler neck at the fuel tank connection. Inspect the filler neck O-ring and the vent hose to the canister before smoke testing. Aftermarket gas caps are a common false-alarm cause on Ford trucks.
Most commonly affected models
F-150 1999–2007Explorer 2002–2005Ranger 2001–2007