Pontiac Repair: 2004 grand am se service engine soon, flasher button, service engine soon light

Question
Hi, 04 grand am se 4cylinder, wife left car out 20degrees below, would'nt start, put inside three days changed fuel filter, put heat in tank and it finally started, but at idol runs real real ruff and the { service engine soon } light is on. After i got it running i also put some injector cleaner in the fuel hoping maybe that was it,,ran it for an hour and no difference. Could it be possible when i put fuel filter on, maybe it is sucking air,,,if you hold the footfeet at a higher rpm it stays there and runs smooth !! I know the electrical part of these cars can mess with a lot so i might mention my turn signals dont work and was told to put new flasher switch in and it would fix the signals and the flasher as it sounds like a clickin noice above the radio where the flasher button is, but didnt get that done as the car froze up,,,i think !! Anyways i got a real ruff idol, service engine soon light on as soon as you turn key on and it stays on, also i noticed when i turned the dome lights on when the car was idling i could also feel it drag the motor down to where it almost died, fan switch and lights also did it to. So i dont know if its electrical, plugs, something needs reset, needs to be driven to bring out the missing, maybe the flasher does not have anything to do at all with it missing !! Any help would be appreciated !! Thanks Jeff

Answer
Hi Jeff....
Was it running OK BEFORE it was left outside?
Was there any precipitation? (snow)
It IS possible you MAY have a sticing injector.
It MAY also be the ignition coil housing.
My BEST advice, if possible would be to get it to a repair shop or auto parts store and have the computer scanned for codes. That will pinpoint the exact cylinder misfiring.
As far as the signal, the hazard/turn signal module is located behind the hazard button (the button is actually the module)
They do ocasionally make noise. If the noise persists, move the steering column up and down see if it stops.
Either way if the noise does not stop, it MAY be the multifunction switch (turn signal switch) located on the column. I have run into numerous switches making this concern.
Please follow post back, if possible.
Pawl