when getting off of freeway the car shuts off its a 2003 ss 3.8 I just had new intake done changed map sensor and a ile control sensor cleaned the mass sensor. sometimes it does ok and sometimes it doesnt. also the idle will be real high like its stuck and when you go to sltop at a light itgoes real low but doesnt stall. then it wants to go on its own when im not even giving it gas.

 

We need a bit more info...
Welcome to the forum.

What year, motor etc would be a great help.
Its kinda hard to tell without the pertinent info
Thanks!
Were here to help.

 

More information would really help. But is some posibilities:
Vacuum leak, Bad, or going bad, IAC or MAS! More info might help narrow it down!