My wife's '03 2.0 zetec has started to stumble or lose power randomly. I have been in the car 3 times it has happened. It happens when we are just cruising along feels like the engine is gonna cut off then it surges and everything is normal. I can't tell if its a tranny issue or an ignition/ fuel issue. Plugs were changed this year autolite platinum. Wires were changed last year. I'm thinking coil pack or injector(s). I just changed the fuel filter a month ago too hoping that would solve the issue. I hope someone can help me I read all the threads with no real mention of anything like this. Any help would be appreciated, I'm a mustang guy and dont really mess with our foci (2003, 2006) all that much. Thanks!