The fuel evaporative emission control canister should be inspected for damage or leaks at the hose fittings every 24,000 miles. Repair or replace any old or cracked hoses. Replace the canister if it is damaged in any way. The canister is located in the engine compartment on all F250HD/SD, F350, and all Super Duty trucks. . The canister is located on the rear crossmember on all F150, F250, Expedition and Navigator models.