2018 Subaru P0440: What It Means & Is It Safe to Drive?
P0440 on the 2018 Subaru: Evaporative Emission System Control System Malfunction. Here's what it means, what usually causes it, what repairs typically cost, and whether it's safe to keep driving.
PowertrainLow urgency
What this code means
A general fault in the EVAP system—could be a leak, stuck valve, or sensor issue.
Common causes on the 2018 Subaru
- 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 2018 Subaru, repairs for P0440 typically fall between $20 and $400, depending on the root cause and labor rates in your area.
Known issues on Subaru
Subaru P0440 commonly traces to the EVAP pressure sensor or a cracked EVAP line. The charcoal canister on AWD models is mounted low and can be damaged by road debris—inspect for physical damage first before using a smoke machine.
Most commonly affected models
Outback 2000–2006Forester 2001–2006Legacy 2000–2006