advice, what to do with my 5sfe Options

[95gtschick]

not looking for more hp or anything, but here are my problems:

-start up in the morning lots of white smoke comes out of the exhaust, but never any other time.

-awful gas mileage - lucky to get 280miles to a tank

-replaced spark plugs... didn't make a difference with gas mileage, but stopped my backfiring kinda.

-noticed that a wire was spliced into one of my ignition wires, thus leaving it with a lot less resistance.

-high miles, odometer says 116k, carfax report said that january 2003 my car had 130k miles (odometer has been rolled back).

-burn a little bit of oil

I don't have an exhaust leak, i already got that fixed, i don't know what else to do. Gas mileage right now is my main concern, cause it costs me $50+ to fill up, and it barely lasts a week and a half. What would you guys do? I just want some advice. Thanks

[95gtschick]

well the idiot who owned the car before me put like, $2 spark plugs in there, so they were crappy already, but they were pretty black when i took them out, don't know if it was oil... they were just solid black. but i put in ngk iridiums, would you guys suggest replacing my spark plug wires?