Checking System For Leaks and Clogging

EVAPORATIVE EMISSION CONTROL SYSTEM (Check for leaks and clogging) - Except evaporative emission canister
If the fuel-vapor vent line is clogged or damaged, the fuel vapor mixture will escape into the atmosphere causing excessive emissions. Disconnect the line at both ends, and blow it clean with compressed air. Remove the fuel tank filler tube cap from the filler tube and check to see if there is evidence that the packing makes improper contact to the filler tube.