Yeah I got the exact same error code on my 2012 Chevy Equinox LS 4 cylinder ecotec 2.4 l. But my crazy ex poured sugar in my gas tank and the car would not start so I took it to the mechanic and he cleaned my tank and switched my fuel pump got it running again but I still was getting p0300 and p0302 codes. Mechanic told me to get new fuel injectors now so I’m currently going to be switching the fuel injectors this week. Car as of right now sputters when I’m at a stop sign or red light not always but usually does and it’ll stall if I don’t rev the engine. Sugar must of gotten into my injectors and causing the misfire. After I change my fuel injectors I will see if the sputtering is rectified and if not I will change the spark plugs.