My '90 sedan deville's mpg is beginning to drop considerably. I usually get around 20 mpg because I drive slow and coast a lot, but recently it seems that i'm getting about half of that. $25-$30 used to cut it for the week, but now its at least $40. The info center is tellin me i'm still getting 19.x MPG though. A little over a month ago i did my plugs, wires, cap/rotor, and oil; this weekend i'm flushing my injectors. The only cause i can think of is a badly leaking gas cap, cuz my exhaust doesn't smell rich. Any ideas?