the "small leak" can be hard to diagnose, it ends up costing more to have it diagnosed and parts replaced than it does to just go ahead and replace them, you can end up paying a $160 diagnosis and they will turn around and say we cant find anything wrong? then you end up paying inflated shop parts prices and labor to "try" this one part.
occasionally it can be the gas cap, replace cap, clear code, 3 days later code comes back lol, or maybe not. cheaper at that point to just shotgun it, takes the average person about an hour to replace all 3 parts, drop the spare down, drop the filler tube down, squeeze the tubes and connectors off, zip tie the air filter to the filler tube, push it back up, pop the hood do the solenoid there, put the spare back up. done. unless you find pellets in the tubes then you have to blow them out with a air compressor.
