i have a 2001 ranger 3.0. The engine idles a little rough but performs well under acceleration and at lower speeds. when the truck shifts into overdrive the engine misses noticeably. (feels like a tire out of balance). sometimes it takes prolonged cranking to start; but it always starts. I have changed the plugs, wires, coil and fuel filter. Today I visited my dealer to have a key cut and coded. the dealer was unable to code a new key because of a failure in the computer that the mechanic said was most probably a fuse somewhere and that this may be the cause of the above missing problem. They did not have time to trace the problem so i left. Does this sound reasonable and does anyone have any ideas what i might do next to try and get my truck running good again? Any advice is much appreciated.