My 06 saturn ion check engine light is on with codes p0300 p1174 and idle roughly when stopped . Could it be the o2 sensor?

Code p 0300 refers to random/multiple cylinder/s--- misfire/s detected ====causes spark plug/s--HT lead/s---injectors/s ( most likely)--ignition coils ---low compression ---wiring---low fuel pressure

check for moisture in coil/s or other electronic connections
code p 1174 refers to fuel measurement system, bank 1 injection timing incorrect===causes fuel pressure/pump---intake /exhaust leak---EGR system---EVAP canister purge valve ---HO2S ( heated oxygen sensor)
the HO2 s is in the exhaust manifold before the cat converter
at this point I suggest a fuel pressure check as random multiple misfires is mostly from bad injectors or low fuel pressure or fuel pressure regulator faulty

There is a technical service bulletin that states the correct procedure to repair this issue is to replace the injectors with updated units AND reprogram the pcm for the new injectors.