P0442 Toyota Highlander
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 Highlander 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 Highlander.
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 Highlander.
Common Causes on Toyota Highlander
- Loose or damaged gas cap
- Charcoal canister cracking from age and heat exposure
- EVAP VSV valve not sealing completely
- Vapor hose connection loose at fuel tank fitting
- EVAP canister filter clogged causing pressure issues
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 Highlander
RAV4 and Highlander charcoal canisters are prone to cracking from heat and age. Located near the fuel tank, they require vehicle access from underneath.