P0440: Evaporative Emission Control System Malfunction
Can you still drive? Yes, this is an emissions-related code and does not affect vehicle driveability or safety.
What Does P0440 Mean?
Code P0440 is a general EVAP system malfunction code indicating that the system is not functioning as designed. Unlike the more specific P0442 or P0455 codes, P0440 does not specify the size of a leak. It may indicate a leak, a faulty sensor, or an issue with a solenoid valve in the EVAP system.
Need to read your codes?
An OBD-II scanner lets you read and clear diagnostic trouble codes from your vehicle's computer. Most scanners work with any car made after 1996.
Browse OBD-II Scanners on AmazonCommon Causes
- Loose or defective gas cap
- Faulty EVAP purge solenoid
- Damaged EVAP canister
- Cracked or disconnected EVAP hose
- Faulty EVAP pressure sensor
Symptoms
- Check engine light on
- Possible fuel odor
- May fail emissions testing
Diagnostic Steps
- 1Check gas cap for proper seal
- 2Use scan tool to command purge and vent valves
- 3Perform EVAP smoke test
- 4Test EVAP system pressure sensor
- 5Inspect all EVAP hoses and connections
- 6Check charcoal canister for saturation
Recommended Parts & Tools
EVAP purge solenoid
EVAP canister vent valve
Estimated Repair Cost
| Type | Estimated Cost |
|---|---|
| Total Repair Cost Range | $20 - $600 |
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Chat with AI About P0440Commonly Affected Vehicles
Related Recalls
1 Active Recall — 2026 Toyota Corolla
The following NHTSA safety recalls have been issued for this vehicle. Contact your dealer to check if your vehicle is affected.
EXTERIOR LIGHTING:HEADLIGHTS
Toyota Motor Engineering & Manufacturing (Toyota) is recalling certain 2026 Corolla vehicles. The front headlights may have missing headlight aim markings, which can result in improperly aimed headlights during service. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 108, "Lamps, Reflective Devices, and Associated Equipment."
Remedy: Dealers will replace both front headlight assemblies, free of charge. Owner notification letters are expected to be mailed April 12, 2026. Owners may contact Toyota's customer service at 1-800-331-4331. Toyota's number for this recall is 26TA05.
Data provided by the National Highway Traffic Safety Administration (NHTSA).
Frequently Asked Questions
Is P0440 the same as P0442 or P0455?
No, P0440 is a general EVAP malfunction code. P0442 specifically indicates a small leak and P0455 indicates a large leak. P0440 could be either or a different type of EVAP failure.
How do I find an EVAP leak?
A smoke test is the most effective method. A mechanic introduces smoke into the EVAP system and visually inspects for where it escapes.
Community Fix Reports
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