hi , i have a 2002 merc sable with the 3.o sohc and 110,000 miles. i bought it this febuary, and it ran fine, but since the warm weather hit it has been acting up especially on hot days . i have had an on going problem with the car getting a nasty hesitation at 4krpms and sometimes reacurring at 5krpms. so far i have replaced the fuel filter, new plugs and wires, crank sensor, and the idle air control valve. it shows no codes when plugged in and just today when idling in my drive way the oil pressure gauge was flahing. any ideas? my next step was replacing the coil pack?