I noticed this weekend that at idle there would be a ticking sound on the passenger side of the truck that was not coming from the motor. It was underneath the rear passenger side door. I got underneath it and noticed it was coming from this plastic canister. Two questions, what is it, and does a ticking sound mean it needs to be fixed? I have no idea what it is, I am thinking an evap canister or something. The truck idles just fine, there are no CEL's on, and it is still getting 14-16 MPG so whatever it is, is not affecting the driveability. It is a 1998 Dodge Ram 1500 318 4x4 with an auto.
^ That is the passenger side Nerf bar for a location reference.