My 91 Eagle Talon 2.0 NT is having problems idleing.. its an auto and it doesn't sound right and idles around 500-550 rpms... it didn't start this till i just filled it up with gas and added 1qt of 5w30 oil into it because it was 1qt low... i am overdue for an oilchange for about 500 miles and i'm taking it in today... what could it be? I'm not to great with cars but know some.. the sparkplugs and wires were just replaced and same with the fuel filter... could it be the injectors or fuel pump? cause sometimes when i press the pedle down for more gas to accelerate it won't go any faster so i keep pushing the pedle more until it downshifts... it was doing great on the last 2 tanks of gas tho getting 33.5mpg on the way back on a trip and on the way there i got 38.7mpg its an automatic i only get the higher mpg if i leave it on powermode on the freeway if i leave it on economy i get areoun 25-27mpg... the gas i just put in it was midgrade at a Phillips 66 just a different location of Phillips 66 that i normally go to.... my car seams to work best on that type of gas so mabe i just have a bad tank of gas?