I have had small idel problem since i got the car its 07 cobalt ss/sc and has ruff idel its at its worst with heater on or when first started at some times it will bounce from 1 to about 2 for the first min and then com down but still bounce???? Then say i pull up to a stop light it will like hick up basically go from the idel at 1000rpm to almost 0 then bounce back up???? Its thrown diffrent codes but i have fixed all of them now the only one i cant get to go away is p1133 its a bank one sensor one insufficiant switching i replaced the sensor and deleted code but it came right back???? Also have changed plugs checked fuel pressure and had my tuner check everything and he says its all good plus i have cleaned throttle body, any idea what this could be or how i can fix it next step is cleaning mass air flow i mean i have gm stage 2 with 2.8 pulley, and im getting 21 miles a gallon !!!!!!!!!!!!!!!!!help!!!!!!!!!!!!!!!!!! Please?????

 

What did the old sensor look like ?Did you relpace it with oem O2 sensor.?
Why I ask is that the sensor could be getting contaminated(burning oil, coolant etc)(Post a pic).


Check the wiring and connectors for problems(pinched or melted toghether)or for a short to ground.
Connecters check for corrossion or contamination and clean with contact cleaner.

Make sure connectors are tight and seated properly on the pcm.

 

Clean your TB.

 

I have this same code and cant get rid of it! Cleaned TB, maf, replaced O2 sensor, but it still wont go away. And my car keeps going rich, like 13.5AFR every few seconds under light load

 

Front o2 sensor needs to be replaced I was told. I think I may give it a shot.

 

I replaced my O2 sensor and it didnt go away. I later saw a thread by darkmanx that said the same thing. Some headers just throw that code, but it doesnt hurt anything

 

ok but if it dose still throw that code then i have no clue why it idels ruff

 

Well it could be the sensor but im just saying just because its that code doesnt mean the sensors bad. Did your MAF get wet by chance? Or is your throttle body dirty?