Ok, I have a 2002 impala ls 3800. When we got it the key wouldn't turn all the way off and we could leave it running and pull the key out. We started having problems with it just dying and wouldn't stay running unless you had your foot on the throttle. I was told it was the ignition, replaced ignition, programmed keys, started it and it wouldn't stay running. We drove it, it started running better but when we killed it the new ignition will not turn all the way off. I have no idea what is going on with this car. Any help would be appreciated.

 

sounds like multiple issues, the key not coming out may be due to wiring or a bad switch in the brake switch/park lock switch system. The not staying running could be many things, have you checked codes or fuel pressure?