Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means there's a problem with the car's system that keeps gasoline fumes from escaping. It's like if the lid on a soda bottle wasn't screwed on tight, and the bubbles could get out.
The P0440 code indicates that there is a malfunction in the Evaporative Emission Control (EVAP) System, which is designed to capture and store fuel vapors from the fuel tank and prevent them from escaping into the atmosphere.
The EVAP system captures fuel vapors from the fuel tank and stores them in a charcoal canister. The vapors are then purged into the engine to be burned. A P0440 code is triggered when the Engine Control Module (ECM) detects a leak or a problem in the EVAP system, which could be due to a faulty gas cap, a leak in the hoses, or a malfunctioning component.
• Check Engine Light is on
• Slight decrease in fuel efficiency
• Fuel smell from the vehicle
• Loose or faulty gas cap
• Cracked or damaged EVAP hoses
• Faulty purge or vent valve
EVAP: Evaporative Emission Control System
ECM: Engine Control Module
• Check the gas cap for proper installation and condition
• Inspect EVAP system hoses for cracks or damage
• Test the purge and vent valves for proper operation
• Tighten or replace the gas cap
• Replace damaged EVAP hoses
• Replace faulty purge or vent valve
• OBD-II scanner
• Vacuum pump
• Smoke machine
$50 - $200
Moderate
• Toyota Camry
• Honda Accord
• Ford F-150
• Ensure gas cap is tightly secured after refueling
• Regularly inspect EVAP system components
• Use high-quality fuel caps
Emission Control System Issue
• Check the gas cap first; it's an easy fix if that's the problem.
• Avoid topping off the fuel tank to prevent EVAP issues.
EVAP system components may be covered under the vehicle's emissions warranty.
P0440 is a common code that has been reported frequently since the introduction of OBD-II systems in the mid-1990s.
Low – This issue does not affect immediate drivability but should be addressed to maintain emissions compliance.
Driving with an EVAP system malfunction may not be legally compliant with emissions standards in some areas.
• Engine at operating temperature
• Fuel tank between 1/4 and 3/4 full
The EVAP system components are typically located near the fuel tank and engine bay.
Q: Can I drive with a P0440 code?
A: Yes, but it's best to fix it soon to ensure your car remains emissions compliant.
Q: Will a P0440 code cause my car to fail emissions tests?
A: Yes, a P0440 code will likely cause your car to fail an emissions test.
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Fitment Required · Vehicle-fitment part
Relevant for some EVAP leak codes where the fuel cap or sealing surface is part of the problem.
Some EVAP leak faults involve the fuel cap or its sealing surface.
Fuel caps vary by vehicle and should be matched to the exact application.
View options on Amazon
Fitment Required · Vehicle-fitment part
Relevant when EVAP diagnosis points toward purge-flow or purge-control faults.
EVAP diagnosis often includes purge-flow and valve-control faults.
Confirm the failed valve and exact fitment before buying parts.
View options on AmazonThese parts may be related to this fault category, but a code by itself does not confirm exact fitment or guarantee that replacing a part will solve the problem.