2000 Explorer with no spark

Hi, I have a 2000 explorer xlt 4x4 with the 4.0L SOHC V6 with about 95k miles on it. I have been losing fuel economy with a few sputters here and there when driving and now it won't start. Took one of the wires off the plug and put a screw driver in and cranked but did not get any spark. Ran the code reader and it did not come up with any faults. Any suggestions before i start throwing parts at it? I'm thinking the coil pack, good spot to start, how to test it?

add to the last post, when i crank the tach does not move off 0. dont know if it usually does or not when cranking, its my dads truck and just trying to make it work again

I had a similar problem with a Jeep Cheroke and replaced the Crank Position Sensor. If that doesn't do it for you, try the Cam Position Sensor. Problems with these two sensors should set an error code.

So problem solved. Bought a new coil pack, that wasn't it. So went and wiggled the wires to the pcm crank sensor and it fired up. Who would have thought