really it's because i've had a problem i have yet to solve, someone told me a bad set of plugs (bosch) which i have installed now were causing a lot of problems. I plan on switching over to motocraft eventually, but it would be a lot easier to just change the easier 4 to see if the plugs are actually the problem.
I know the problem lies somewhere in the ignition system. But trying to figure out which component is really giving me a major headache. Sometimes it will buck and back fire terribly. But I never get a check engine light, and it's so inconsistent and random that i can never find a fault when i go to test anything. I'm really just trying to eliminate as many possible problems as possible without going out and blowing a bunch of money changing good parts.