First I would like to that everyone in advance. I am new to this forum and just need a little advice. Have an '07 Cobalt 2.2 with 28k miles. At about 27k miles it started to miss a little at idle when it got up to operating temp. Then just recently the miss became very bad and finally got a P0300 code which is engine misfire. I checked the spark plugs and they are white indicating that the motor is running lean. A friend told me there is a TSB that states you have to change all the injectors and reprogram the computer. The vehicle is not under warranty because it is a rebuilt title. (Roof damage from a tree falling on it) so nothing that would affect the motor.
Any ideas other than that TSB ? I just want to see some opinions before I go through the expenditure.
Thanks in advance,
Eric