Car stalls when put in gear

I have a 2000 sunfire and over that last 6 months my car has stalled about 10 times on me. it's when i back out and then put it in Drive, the whole car turns off and i have to restart it. i have taken it to a mechanic and they scanned it and found nothing wrong. does anyone know what the problem could be? is it something with the transmission?

I have a 2000 sunfire and over that last 6 months my car has stalled about 10 times on me. it's when i back out and then put it in Drive, the whole car turns off and i have to restart it. i have taken it to a mechanic and they scanned it and found nothing wrong. does anyone know what the problem could be? is it something with the transmission?

Is it a 2.4L? Mine does the same thing. Someone told me to check the throttle body and make sure everything is clean and connected right and the vac lines are okay. I noticed the vacuum line was lose. I pushed it back in and that seemed to help for a week then it started again and the line was in right. I didn't find anything wrong with the tb, but maybe you will. Good luck