What P0442 means
Diagnostic Trouble Code (DTC) P0442 stands for Evaporative Emission System Leak Detected (Small Leak). This is a generic OBD2 diagnostic trouble code indicating that the engine computer (ECU) has registered an operational anomaly in the powertrain (p) systems.
When this error registers, the ECU records a freeze frame of sensor data and lights up the Check Engine Light on your dashboard to notify the operator of a system fault.
Symptoms of OBD2 Code P0442
When code P0442 is active, your car might exhibit the following common symptoms:
- Check Engine Light on
- No performance changes
Common Causes of Code P0442
Faults that trigger this code typically include:
- Cause 1: Gas cap seal worn, dirty, or slightly loose
- Cause 2: Small pinhole leak in EVAP hoses or charcoal canister
- Cause 3: Faulty EVAP system pressure sensor
- Cause 4: Weak seal on the purge valve
Can you drive with a P0442 code?
Yes, it is fully safe to drive. The small leak does not affect engine performance, but will trigger the Check Engine Light and fail emissions tests.
Expected Repair Cost Band
$10 - $30 for a new gas cap. EVAP hoses or solenoids range from $100 to $300.
Related Diagnostic Trouble Codes
If you have scanned multiple codes, see these related guides for troubleshooting context:
Frequently Asked Questions
It refers to a leak of vapor equivalent to an opening of 0.04 inches or smaller.
If you tighten a loose gas cap, it can take several days of driving for the vehicle's computer to automatically clear the light. OBDAssistant can clear it instantly.