What makes your 1997 Ford F-150 pickup jerk?
You may want to check for last tune up. I had a similar problem with my 99, my plugs were the problem Be shure you have double platinium plugs on it. it may also be the voltage in the plug wires being so high, that the plug wires need to be either not touching or replaced. i replaced mine with higher quality spark plug wires. Sounds like one of the coils is going bad. May take several hundred miles before it throws a code. Easy to replace. i would change out the sparkplugs and sparkplug wires. wires usaually break down over a period of time.