My 2000 3.0L 4x4 has severe driveability issues. It started about month ago. The engine starts to stumble and misfire and is barely driveable. I found if I disconnect the negative battery cable, the computer resets itself and the vehicle is driveable again, but it does not last(about 30 miles). I changed the plugs and wires also the crankshaft position sensor. The problem still exists.