nxpoweredsr20

i rescently picked up my first 240sx with a automatic transmission. It is having a intermittent idle issue i think is linked to the torque converter but would like a second opinion before i change it out. when taking off from idle sometimes it just revs up to around 2k rpm before it goes into gear making me think its not engaging. Also sometimes when comming to a stop it still wants to creep foreward with brakes applied and when i get to a complete stop it droppes to 500rpm and dies. making me think its not dis engaging. And the only check engine light that is on is for a egr insuffiecint flow? im stumped. any help is great guys