2002 buick century jerking problem

My first post guys please bare with me....so I got this car and I been working on it...had the check engine light on gave me code p0300 ...replace lower & upper intake gasket since that is a major fault with these vehicles.replace icm and all 3 ignition coils plus wires and spark plugs. So now it gives me a p0302 code and the car is jerking alot from 10-80 mph. and I check the wires and spark plug again to see if it could b that.but everything seems normal....I even went to replace the camshaft sensor...so now I need help to find what else could b cause this...and I dnt want to check the injectors cause it will b a pain lol so any ideas would b greatly appreciated! Thanks

I would take a closer look at the complete ignition train for the #2 hole, possibly including swapping a couple coils to see if the missing cylinder moves.

Yea I will try....all three coils are brand spanking new just replace them