ok im sorry for no pics i dont know how to do it,but on the passenger side of the truck right to the back of the cab under the cab attached to the frame there are 2 'what look like containers'. one is rectangle 6x8x4,and right next to it almost touching it there is a round one 'cylinder 8in tall and 4in round.it almost looks like a filter can go in the round one but it cant be opened.does anyone no?

 

evap canister for the evap system

 

evaperator system for the ac?

 

Evap cannister. it's for emissions.
It filled with activated charcoal. It stores raw fuel vapours when the gas tank vents. Raw fuel is a serious polutant.