99 olds 88 3800 missfire at idle p0301

hi everyone im new to this forum. anyway my olds had a check engine light on and a missfire at idle revs out fine i checked the codes and it was a bad o2 sensor. replaced the o2 and still had a missfire at idle and now i get a cylinder 1 missfire.. it has new ac plugs,wires and i replaced cylinder 1's injector. still has a cylinder 1 missfire. the coolant levels are stable and when i did the plug change cylinder 1 was a little black not oil black fuel black i figured i had a leaky injector. anybody have anythoughts..thanks mike

Welcome to AF, can you feel this miss at idle, if you kill #1 cyl. is there any change in engine idle?

you can feel it at idle if you power brake it you can feel it miss more but if your driving it you dont feel it at all except at idle the exhaust does smell rich

Check the wire to to # 1 check, for spark at that cylinder, could also be a bad plug, all these suggestions are pointed towards basic diagnostics for an obvious misfire in a specific cylinder.

i thought of the spark issue but i was told that if a coil pack is bad youll get a missfire on the two cylinders that the coil feeds.

Maybe maybe not, how hard is it to check for spark, takes less time then this post did.

im going to try it tommorow and ill get back to you thanks for the input maxwedge.

ok here is an update sorry it took so long ive since replaced the plugs and wires again and the coil also replaced the maf sensor. still has a rough idle but clears up as soon as you hit the gas. could a leak on the intake cause this. no coolant loss all plugs look good but #1 appears black not oil black but fuel black at idle you can smell its running rich

That injector could be leaking down, causing this.

moved the injectors around today no differance i put a brand new ac fuel injector in anyway , also replaced the pcv valve. the only thing im left with is internal bent or burnt valve but this thing runs fantastic as soon as you get it off idle so it may just be carboned up i guess or maybe the seat has sunk. ill do a compression test tommorow and get back to you..