What usually causes it
- A loose, cracked or wrong gas cap
- A cracked hose or a leak in the fuel filler pipe
- A stuck purge or vent valve
- A cracked charcoal canister, the part that stores the fumes
P0440Starts at: OK to drive, fix when convenient
Fuel vapor (EVAP) system problem
The EVAP system traps gas fumes from the fuel tank so they do not escape into the air. The computer found a general problem with it.
Check this first
Tighten the gas cap until it clicks, and check the cap seal for cracks. The light can take a few days of driving to turn off.
What to watch for
- A strong smell of gas
- Fuel dripping under the car
- The gas pump clicking off again and again while you fill up
Can I keep driving?
We rate P0440 as OK to drive, fix when convenient, as a starting point. Keep an eye on the signs below. If the light starts flashing, stop driving soon.
Quick answers about P0440
What does P0440 mean?
Fuel vapor (EVAP) system problem. The EVAP system traps gas fumes from the fuel tank so they do not escape into the air. The computer found a general problem with it.
Can I keep driving with P0440?
We rate P0440 as OK to drive, fix when convenient, as a starting point. Keep an eye on the signs below. If the light starts flashing, stop driving soon.
What usually causes P0440?
The most common causes, in order: A loose, cracked or wrong gas cap; A cracked hose or a leak in the fuel filler pipe; A stuck purge or vent valve; A cracked charcoal canister, the part that stores the fumes.
Estimates only. A mechanic should confirm. The same code can mean slightly different things on different cars; the app explains it for your exact year, make, model and mileage.