2005 Kia Spectra chacing a missfire

i have a 205 kia my friend put 2 gal of 2 stroke in it i imediately put a full take of regular in to dilude it called for missfire on cyl 3 got spark found lack of spray on injector replaced injector car ran like a beat 70 miles light again miss fire 1.2.3.4 found bad wire replace wire for cyl one caseing was broken all the way dow white instlation was outta caseing cleared codes good for 50miles pulling codagain miss cyl 4.cleared for curiosity came again miss cyl 1 car runs like a champ till 3k rpms then loses all power till below 3k again at a loss thinking fuel filter? car has 250k 70 on engine and trans all cyls a 48 psi compression...check engine light was on night before 2 stroke went in but wasnt flashing after 2 stroke flashing car over heated once i stoped while run cooled down in second never happened again aafter adding water