[Green Machine 95]

I recently just changed my plugs, I had AutoLite and switched to AC Delcos, When I first had them in it ran really good, but a few days of driving its been running a little rough, I tried fuel injector cleaner (STP brand) and that didnt work, I am going to have it checked out tomorrow, at first I thought my trans was going because it was running rough, but I always think of the worst situations...I am still hoping its something little, thanks