Need Help With A 2004 Aveo

Hi I got a 2004 Aveo like couple weeks ago and Now I am having [COLOR=#739912 !important][COLOR=#739912 ! important]engine[/COLOR][/COLOR] trouble because my check engine light is blanking and it is missing bad(Miss Firer).I took it to a garage and the guy put a scope on it and here are the codes: PO300,P1781 and cylindar #1 aint getting no compassion and I replace the [COLOR=#739912 !important][COLOR=#739912 !important]spark [COLOR=#739912 !important]plugs[/COLOR][/COLOR][/COLOR] and spark wires and it is still missing.Also my car has hardly no power at all.Need help?Heres my email Singer44730@yahoo.com