Stalling when in park and idling, and now at higher speeds.

What is your question?

The reading we get is that cylinder 1 is not firing, we've replaced spark plugs, even bought platnium, it ran worse had to replace that, and at first it does do better, than a few days later it just starts sputtering in idle and park, and today at 50 miles per hour it cuts out and sputtering, and I noticed when in idle the oil pressure goes to 20 unless you give it alittle gas? Any suggestions. We've changed out the coil, and a few other things?