Could be a vacuum leak or intake system leak,once I was getting stalls while coming to stop along some rough IDLE it resulted to be an intake boot getting loose on both sides(MAF and Intake port on the engine itself)
After I've tighten it everything came to normal,in my case some mechanic forgot to tighten the bolts properly,I was glad to discover that.
Check for leaks they are always causing this kind of issues.