Every 38,000 km or every two years.
The EVAP system performs the function of removing fuel vapors from the fuel tank and fuel system, concentrating them in a carbon adsorber and then burning them during normal engine operation. Typically, this system is installed only on vehicles equipped with catalytic converters.
The most typical sign of a malfunction in the fuel vapor recovery system is a strong smell of gasoline in the engine compartment. If you smell this, inspect the carbon canister and hoses (arrow) of the system for cracks. On most models, the canister is located in the front corner of the engine compartment.
For more information on the fuel vapor recovery system, refer to Chapter Engine management and emission control systems.