All codes
P0442Emissions System
EVAP System Small Leak Detected
Fix P0442 evaporative emission system leak. Learn common causes of small EVAP leaks and how to find them.
What you may notice
Symptoms
- 01Check engine light on
- 02Fuel smell near vehicle
- 03Usually no drivability symptoms
- 04Failed emissions test
Where to look first
Common causes
- 01Loose or damaged gas cap
- 02Cracked EVAP hoses
- 03Faulty purge valve
- 04Leaking charcoal canister
- 05Fuel tank leak
A sensible sequence
Best diagnostic order
- 01Inspect and reseat the fuel cap.
- 02Smoke-test the EVAP system correctly.
- 03Test purge and vent valves before replacing the canister.
Step by step
What to check and repair
- 01Check and tighten gas cap first
- 02Replace gas cap if damaged
- 03Smoke test EVAP system
- 04Inspect all EVAP hoses
- 05Test purge and vent valves
What Does P0442 Mean?
P0442 indicates that a small leak has been detected in the EVAP (Evaporative Emission Control) system, which captures fuel vapors from the tank.
Common Culprit
The most common cause is a loose or damaged gas cap. Always check this first before more extensive diagnosis.
Finding Small Leaks
Small EVAP leaks can be challenging to find. Smoke testing is the most effective method for locating the source.