how can i check EVAP Canister/hose on Ford Ranger?

I have the 'check engine' light on, I went to get it checked and they gave me the code- P0457 EVAP small leak detected. ECM has detected a large leak in the EVAP System during a system monitor test. Probable cause- defective, loose or missing gas cap. - EVAP canister broke, hose cracked or not connected. Purge or vent solenoid defective- Vacuum leak at engine. I notice a fuel odor when the truck is on and the gas mileage / MPG. Is lower then average. If I drive 45 Minutes down the freeway, the gas odometer goes down like if the gas tank had a leak. Is there some way to check the Evap Canister/hose or the Vent solenoid ? where is it located? Is it expensive to fix?
I tried to find it on Google but couldn't a accurate diagram...
2002 Ford Ranger XLT

Shannon2016-03-20T08:13:37Z

Yes it sounds like the previous owner removed the MIL lamp or it burned out (the MIL should illuminate with KOEO (key on engine off) If it does not, the lamp should be checked. Emission waivers are not granted until a certain dollar amount has been reached to attempt to repair the problem! Also the most common things in the EVAP system ( even though you failed to provide the engine option of your vehicle (ie 2.4,3.0,4.0) to malfunction are 1.The purge flow sensor and 2. the purge control valve/solenoid. Although instead of just throwing parts at the vehicle you should you should take it to a reputable shop where you can have it properly diagnosed (not auto zone all they do is read codes, They cannot view datastream which is necessary to properly diagnose a vehicle!)

1wbrockstar20042014-06-11T21:42:18Z

The evap system starts at the gas cap,then the vent valve(on top side of gas tank)next a long vacuum hose runs from the vent valve all the way to canister.Then you got another vacuum hose from the canister to the purge valve,finally another vacuum hose from purge valve to intake vacuum fitting.The purge valve is between the carbon canister and intake fitting.It should make a clicking noise when you turn the key on.If there is no clicking noise,disconnect harness and check for battery voltage.If no voltage,check control unit and wiring for shorts and opens.Only vapors are supposed to be sent from tank to canister,not fuel.To test for vacuum leak,let engine run,spray carb cleaner around every gasket,vacuum hose,and vacuum operated component.If the engine idles up,down,smooths out,or the engine stalls you have found the leak.Spray vent valve,all vacuum hoses,canister housing,purge valve,intake fitting.Check the gas cap gasket and make sure the cap vents(around edge)are not clogged.