Basic checks
Veepeak OBDCheck BLE
A Bluetooth LE adapter for reading standard engine codes and supported live data.
View on AmazonP0442
Evaporative Emission System Leak Detected (Small Leak)
Moderate severity
This code indicates that your car's computer has found a minor leak in the system designed to prevent fuel vapors from escaping, often caused by a loose gas cap or a small crack in a hose.
The Powertrain Control Module (PCM) has detected a small leak in the Evaporative Emission (EVAP) system.
Common causes
- high
Loose, missing, or faulty gas cap
A gas cap that isn't sealing properly is the most common culprit for small EVAP leaks.
Typical part cost: $0-30 part
- medium
Cracked or disconnected EVAP hose
Inspect all EVAP hoses for small cracks, chafing, or loose connections.
Typical part cost: $20-100 part
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First things to check
- 1Tighten or replace gas cap
- 2Visually inspect all accessible EVAP hoses and connections
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Tools you may need
Already have a compatible scanner? Use it. If not, a Bluetooth OBD2 adapter can help you confirm engine codes and check supported live sensor data before replacing parts.
Regular diagnostics
vgate iCar Pro BLE 4.0
A Bluetooth LE adapter with an automatic sleep feature for routine code and sensor checks.
View on AmazonAnother option
OBDLink CX
A Bluetooth LE adapter to consider when comparing supported vehicles and diagnostic apps.
View on AmazonIllustrations shown, not product photos. Check vehicle, phone and app compatibility before buying. These adapters do not guarantee access to ABS, airbags or manufacturer-specific systems. Clearing a code does not repair the fault and can reset emissions readiness monitors.
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Related codes
See related trouble codes
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Frequently asked questions
Can a P0442 code clear itself?
If the cause was a loose gas cap, tightening it might allow the code to clear after a few drive cycles, but it's best to manually clear it after fixing.
What is the most common fix for P0442?
The most common fix is simply tightening or replacing the gas cap, followed by inspecting and replacing any cracked or disconnected EVAP hoses.
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