random misfire codes after changing spark plugs. CAR RUNNING VERY ROUGH on 2002 Infiniti I35

had my sparkplugs changed and was told oil was found in one. had both gaskets replaced and now my car is running HORRIBLE!!!It is sputtering and i am getting only 10 mpg engine codes are P0300, P0223,P1224, P1122. in addition, both the check engine and airbag lights are blinking.

Asked by for the 2002 Infiniti I35
take back to mech something is def wrong.