So, I did a little research on this issue before taking it to the dealership. It was one of two things, 1). A/C Drain Tube. @). Heater Core. After I dropped it off at the dealership, they called me the next morning saying that the couldn't replicate any of the issues I was having (i.e. hissing noise and hot liquid above gas pedal.) What they DID tell me was that my A/C Drain Tube was extremely clogged with leaves, dirt, and other debris. Said that a tech took compressed air to it and blew a whole bunch of stuff out. The service manager told me that that would most likely resolve the issue. Upon driving it to and from work today, there is no more issue. They also didn't charge me for this, not even for the diagnosis! Thank you for all of the input on the issue, this was really stressing me out.