OK where to begin..I have a 2002 V6 ls the problem is my car serging at idle when im at a stop it will bounce between 600 and 900 rpm and the car has a small vibration while standing still. if i put it in neutral the idle serge will stop.tranny? also from time to time ill be at a red light or stop sign and the car would just shut off. starts right back up with no problem. i didnt have a check engine light until today and when i got it read they said it was my O2 sensors but i kno those wouldnt cause the serges. has anyone ever had any of these issues and if so HELPPP!!!! any advice would be taken.. thank you...