If they are the original wires throw them as far as you can from you - they are junk! Your year of tour should give you misfire codes - got code? Also remember - there is no such thing as 100K plugs (Yes, they may work that long but with the price of gas why keep them when the efficency is degraded?) There is no such thing as a maintenance free battery.
Tell us if you are getting misfire codes. The fuel pressure is usually 30 and idle and 40 running. Yours is a returnless system if you have a 99. I don't know the idle pressure for them off hand.
