Impala 2004 start, but when engage to drive it turn off

I think i know what the issue is. i have the same car and it happened to me.. It sounds like your security system is failing and not allowing your car to start. I found a module that you can install yourself and your car will start every time . Your car is on the list year make and model for this problem. Check out the site and if for some reason it foes not work they refund %100 of your money.. Ask questions they are very helpful . hope this helps ya
http://vatspasslockpasskeysecurityhelp.com/ Do It Yourself GM Security bypass