P0442: Evaporative Emission System Leak Detected (Small Leak)
The EVAP system found a small leak, about the size of a pinhole.
Green, yellow, red: three ways P0442 can look
The same code can be a quick fix or a reason to pull over. Match your situation to the closest example.
Keep an eye on it
Light on, nothing else. Safe to drive; start with the gas cap.
Schedule a repair
Code returns or inspection is due. Get a smoke test to find the leak.
Stop and get help
You smell fuel strongly or see a leak. Don't drive it.
Symptoms you might notice
- Usually none
Common causes, cheapest first
- Gas cap seal worn
- Cracked EVAP hose
- Leaking purge or vent valve seal
- Cracked filler neck
What you can check before calling
- Replace the gas cap if the seal is cracked
- Make sure the cap clicks
A code points to a system, not a part. Replacing parts based on the code alone is how people spend money without fixing the problem. Testing confirms the cause first.
Want the full story? Read our guide: Check engine light after getting gas? Gas caps and EVAP codes.
Generic codes (second character 0) mean the same thing on every vehicle. Some manufacturers add their own details, so check service information for your exact vehicle.
Related codes
More evap (fuel vapor) codes
- P0440
Evaporative Emission System Malfunction - P0441
Evaporative Emission System Incorrect Purge Flow - P0446
Evaporative Emission System Vent Control Circuit Malfunction - P0449
Evaporative Emission System Vent Valve/Solenoid Circuit Malfunction - P0457
Evaporative Emission System Leak Detected (Fuel Cap Loose/Off) - P0496
Evaporative Emission System High Purge Flow
Look up another code
Cummins fault code (like 1922), J1939 SPN and FMI (like SPN 3251 FMI 0), or an OBD-II code (like P0420).
Questions
What does P0442 mean?
P0442 means "Evaporative Emission System Leak Detected (Small Leak)". The EVAP system found a small leak, about the size of a pinhole.
Can I drive with code P0442?
It depends on what the vehicle is doing. Green: Light on, nothing else. Safe to drive; start with the gas cap. Yellow: Code returns or inspection is due. Get a smoke test to find the leak. Red: You smell fuel strongly or see a leak. Don't drive it.
What causes P0442?
The most common causes are: gas cap seal worn; cracked EVAP hose; leaking purge or vent valve seal.
Is P0442 a serious code?
It can be. You smell fuel strongly or see a leak. Don't drive it.
Skip the shop. We'll come to you.
Book online in about a minute, or call or text the office. We'll confirm the details and get a mechanic headed your way.