P0442 Toyota 4Runner
EVAP System Leak Detected (Small Leak) · Powertrain Code · Low · Repair: Easy
What is P0442?
A small leak has been detected in the EVAP system. Common causes include a loose or cracked gas cap, cracked EVAP hose, or faulty purge/vent valve.
When the Toyota 4Runner triggers code P0442 (evap system leak detected (small leak)), it typically points to an issue in the powertrain system. Below you'll find the most common causes, symptoms, and repair options specific to the Toyota 4Runner.
This repair is rated easy, meaning basic tools, no lift needed.
Diagnostic data on this page is compiled from publicly available repair resources and technical service bulletins. Always have a qualified mechanic confirm the diagnosis before authorizing repairs on your Toyota 4Runner.
Common Causes on Toyota 4Runner
- Gas cap seal worn from dust and debris exposure
- Charcoal canister damage from off-road use
- EVAP vacuum switching valve (VSV) failure
- EVAP vapor line damage from undercarriage contact
- Fuel tank vapor hose connector corrosion
Symptoms
- Check engine light illuminated
- Faint fuel smell near vehicle
- Slightly reduced fuel economy
- Failed emissions test
- Occasional rough idle after refueling
Notes for Toyota 4Runner
Tacoma, 4Runner, and Tundra models used off-road frequently develop EVAP issues from canister contamination and line damage.