why does the car stall when i come to a stop

i bought the car and it had the check engine light on... took it home and later that day noticed it started to idle funny. then i noticed the idle air control valve was disconnected i plugged back in and it started to stall when left idling for a little bit or when i came to a stop. checked the codes and 6 codes popped up. but it was only 3 different codes each one just popped up twice. P0506, p0507, p0741. i replaced the the idle air control valve, it idles better now but when im driving the car and i come to a stop the car truns off, but starts right back up. so what ive been doing is when i stop i put the car in neutral and keep on the gas a little so the car stays on...whats going on please help!