my car seems to stall out at anytime when it feels like it, but only when your braking. like if I am comming to a stop light and I stop fast(not a panic stop) it sometimes stalls, and if I am turning a corner sometimes it stalls. my old engine did this so I know its not the new 1 I put in. is this a sign I need a new iac or tps?

clean the iac.. it might be gummed up and not opening when it should..
try swapping in your old iac if you still have it..

Yeah, sounds like the IAC.