1998 Ford Explorer mabe fuel

Shakes or Wobbles problem
1998 Ford Explorer 6 cyl Two Wheel Drive Automatic 105k miles

Well as of reasently my truck has started to shake at idol so I took it to get it scanned to see what the problem is and it told me that my number one and number four cylinders are fouled out (The two closest to the front of the engine) so I first changed the ignision coil, then I changed the spark plugs and wires, it still chugs at idol and I have changer the two fuel injecters, there are no vacume leakes, and I was told that it mabe a fuel pressure regulator. I have to know what to do so this truck doesn't nickel and dime me. PLESAE HELP! Darryl