2.2L stumbling.
 

Help! I recently purchased a 2.2L chevy cobalt.
most of the time while trying to pull out from an idle stop ( red lights, or stop signs) when i hit the fuel. The car just kind of revs for a second and doesnt do anything. I normally have to pump the fuel a few times before it actually will catch and go. This started as just an annoying pain, but after being nearly hit several times due to not being able to pull out fast enough it has become dangerous. I've done alittle research and talked to some local mechanics, a few people are saying it might be the cam sensor. However when looking through forums i discovered the 2005 cobalt does not have a cam sensor....a few people are saying it could be a spark plug problem?
also engine light is on for o2 sensors, bank 1 sensor 1 and bank 2 sensor 1. There is NO catylitic converter on the car. im not even close to being any sort of mechanic..
lastly the strangest part is when i stop the car at a red light, or stop sign while the radio is on, the music becomes extremely loud, like someone just turned up the volume. ????? I think my car is haunted.
​​​​​​​oh yeah, also from time to time while driving the steering wheel will jerk slightly to one side, this has never caused me to lose control but has scared my wife and is causing me an ear full everytime.

o2 sensor codes could definitely cause the car to stumble. what are the codes?

For the stereo volume changing, there's a setting called Auto Volume (Speed Compensated Volume). The information below is from the 2005 owner's manual.

AUTO u (Automatic Volume): With automatic volume, the audio system adjusts automatically to make up for road and wind noise as you drive.
Set the volume at the desired level. Press this button to select LOW, MEDIUM, or HIGH. AUTO VOL LOW, AUTO VOL MEDIUM, or AUTO VOL HIGH will appear on the display. Each higher setting will allow for more volume compensation at faster vehicle speeds. Then as you drive, automatic volume increases the volume, as necessary, to overcome noise at any speed. The volume level should always sound the same to you as you drive. AUTO VOL NONE will appear on the display if the radio cannot determine the vehicle speed or if the engine is not running. To turn automatic volume off, press this button until AUTO VOL OFF appears on the display.