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P0440: Evaporative Emission Control System Malfunction
The fuel vapor recovery (EVAP) system has a fault.
Low Severity
$5 – $400
Can I Keep Driving with Code P0440?
Yes, the car runs fine but you may notice fuel smell or fail emissions testing.
What P0440 Means
The EVAP system captures fuel vapors from the tank and routes them back to the engine. P0440 is a general fault code, often caused by a loose gas cap.
Common Causes
Diagnostic Tips
- Always tighten or replace the gas cap first, the cheapest fix possible.
- Drive 50 to 100 miles after tightening to let the code clear.
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Will a gas cap really fix P0440?
Surprisingly often, yes. A bad seal lets the system fail its leak test.