Mis-fire Cyl#1

I have a 1997 Escort that I'm trying to sell. Right when I go to sell it out of my front yard it starts to mis and idles rough. I had it scaned because the "check engine" lite is on. A auto tech said the MAF sensor and spark plug #one is sometimes mis~firing. I replaced the MAF sonsor, Coil Pack, Spark plugs and spark plug wires. I still have the same problem?