my 01 focus is only geting spark to 3 cylinders. I replaced the wires already but i still get no spark when i pull the plug wire.. i wa thinking it might be the coil i hear so much talk about.. any ideas or help would be great. it has about 125000 milesand has always run like a new car. no leaks or anything yet no overheating ac works etc

No spark out of the coil on one cylinder, is most likely a bad coil. Cylinders 1 & 4 fire from one half of the coil, and 2 & 3 fire from the other half. There are two circuits in each half of the coil and it is possible for only one of the two cylinders to fire.