Well my neon had been getting about 30 mpg, then it suddenly started getting 17-20 mph with out any warning at all. I've replaced all the "normal" stuff (both O2 sensors, thermostat, coolant sensor, ect) within the past 4-5 months but nothing has fixed this. I was getting a code for a shorted downstream O2 but that went away after i replaced it. I'm also getting a "low engine temp" code but when i check it the computer tells me its at 190+ degrees (i bought a computer reader). I'm not sure what else to do with this. Could this be a problem with my computer? I never drive this hard at all. Any help would be much appreciated. Thanks

Okay my Dodge Neon is a pain in the ass. I spend $20 to fill up my gas tank, paying the average of approximately $2.85/gallon. And within three days, I gotta refill. There's no leak, but it burns a hell of a lot of gas. And my mother is another pain in the ass who refuses to believe that $20 fills up my tank; she also swears on her life that she bought this car because it's good with gas and that I can travel to the end of the earth and back on a full tank; basically, a full tank should last me a while. Yeah well, it doesn't. I drive maybe 25 miles a day and by the middle of the fourth day, I'm down to nothing. There's no leak, there's no problem. But what the hell is up with my car? Is it just this insane gas machine?