It seems that whenever my Subaru Forester has been sitting for long periods of time, e.g. parked for 6-7 hours while I’m at work, whenever I drive it again I can hear strange liquid noises coming from the dashboard - almost as if there is water sloshing around in there. I live in Florida and use my air conditioner a lot - my only idea is maybe the condensation from my air conditioner isn’t properly leaking out of the car? Any thoughts/ideas? The check engine light also seems to come off and on sporadically…
Regarding the sloshing noise, you probably need to have the drain for the A/C system condensate cleaned out. In addition to the annoyance of the sloshing noise, you will get to the point where the collected condensation sloshes onto the carpeting when you make a sharp turn. Additionally, you are allowing a situation to exist that favors the growth of mold and other fungi. Have the drain cleaned out with compressed air a.s.a.p.
As to the Check Engine Light, nobody here has a crystal ball. While it surely has nothing to do with the sloshing noise, the other possibilities run into the hundreds or thousands. Have the stored trouble codes read–free of charge–at an auto parts retailer, and then post the codes (the format is along the lines of “P1234”) here for specific advice.