Trouble code
P0442
Evaporative Emission System Leak Detected (Small Leak)
What P0442 means
A small leak in the fuel vapor system, typically a pinhole or a slightly imperfect seal.
Symptoms you may notice
- Check engine light only
- Failed emissions test
Common causes, cheapest first
- Fuel cap seal worn or not seated
- Small crack in an EVAP hose
- Leaking purge or vent valve
- Pinhole in the charcoal canister
Before you buy anythingSmall leaks are genuinely hard to find without a smoke machine. Start with the cap, then inspect every rubber EVAP line for cracks where they bend.
What to do next
- Confirm the code with your own scan tool, or have it read free at a chain parts store.
- Decode your VIN so you know your exact engine and build date.
- Work down the causes above from cheapest to most expensive.
- Search NHTSA for a recall or service bulletin covering this symptom on your vehicle.
- Read the engine buying guide before ordering.
P0442 is a generic OBD-II code, standardized across every make and model sold in the US from 1996 onward. The meaning is the same on any vehicle; the specific part and its location are not.
Parts
Parts commonly needed for P0442
These go to Amazon. We earn a commission if you buy, at no extra cost to you — see our affiliate disclosure. Which one you actually need depends on diagnosis — read the note above first.
Confirm fitment against your VIN on the listing page before ordering. A part that matches your year and model can still be wrong for your build date or engine code.