The first thing I did was change the fuel filter. I went to the store and got a FRAM fuel filter for like $20 or so. Just to be safe, I ran the car about 500 miles, and changed the filter again because who knew how nasty the fuel system was!
Then I took out the old distributor cap and rotor, and replaced them with a performance unit for about $15 or so. The old rotor was horribly corroded.
Then I removed the old fuel injectors and put in OEM Ford Taurus injectors, because the old ones were disgusting too.
I then removed the spark plugs and spark plug wires, and put in my performance Beru Silverstone plugs and Magnecore wires.
I then paid the $700 or so to get the heater core replaced (it was too time consuming for me).