00 Neon 4 cyl auto 63500 miles Had a miss in #1 cyl took out the plug to find tracking marks on the outside of the plug.So i put all new plugs ran ok for 2 days then back to the miss again more tracking on the plug again.So in went new plug wires and new plug in #1 cyl ran good for about a week this time! then another miss this time #2 cyl had tracking on the plug. What can be happening here?

my 93 chev. ck-1500, reg. cab, 4.3 litre, 4l60e trans. it will start and when i put it in gear, idle will drop and it dies. the last time it did it, i babied the throttle and got it going but was sluggish on pickup when i pressed on the gas. when i got home i scanned it and got a map sensor too high reading. plugs are good, wires are good, replaced coolant sensor some time back. air filter is good, ran injector cleaner through it, also put drygas in it. it has 177,000 miles on it, fuel pressure is 10 lbs. injectores seem to be spraying ok. oxygen senor is working fine. although mileage is down some. i replaced the base gasket on the tbi. it was leaking. this happened after that was replaced. the most constant sign is it dies when i shift it into gear. i cleaned the base of the tbi when i removed it. the egr seems to be working, it ran rough when i pushed it in manually when idling. if the knock sensor reads 5 when idling will this retard the timing and cause problems. sometimes reads as high as 16 going down the road.can you help with this one? thanks.