2001 Chrysler Sebring Stalling

I have a 2001 Chrysler Sebring Convertible V6 2.7 engine. I just had to have my engine rebuilt after it dying all of a sudden. One day Im driving on the freeway and noticed my car smoking like a forest fire. I had no prior signs that anything was wrong. No lights came on or nothing. After finding out the engine was shot I had a reputable mechanic put a rebuilt engine in for thousands of dollars. After driving it for a few weeks now I noticed that everytime it gets warm when I come to a stop light or become idle it sputters and if I dont press on the gas right away it will shut off. It starts up right away and while driving it runs fine but as soon as I slow down to stop again it wants to shut off. Please advise.