silverbullet08

Well i got tuned last night again and im still having issues. THe car runs amazing at wot and everything is right on but when i drive in traffic my idle sits at 1200rpms til i come to a complete stop. we tried another tune and then the car threw a crank relearn code P0315. What do yall think this is? i tuned for 60lbers 2.7 and a cat delete. i was stage 2 before this. and not to mention the car really doesnt feel any faster at all really?