My 2012 Kia Sedona has a rough idol and wants to stop running at stop signs. The check engine light come on. It is about -30 degrees outside could that be the issue.

SOURCE: 2000 kia sportage ex, 4 cyl.

Many of the Kia sportages have a problem with the coils.

There are 2 coils for each 2 cyl and they are located under the middle platic cap on the valve cover.

These coils will set a check engine light that blinks when misfiring and stays on steady when the motor is running smooth. Autozone or Advance auto have a scanner that can check all engine functions and will show a problem with # 2 and 4 cyl.

The coil packs are $39.00 to replace but check the codes first

SOURCE: 2002 KIA Sedona running rough

i may have an answer for you i have an imported v6 3.8 it has recently developed similar problem, i have been looking on www.kiatech.com whcih is very informative, there is a technical bulletin on my model (06) that refers to possibility of faulty o2 sensors which may or may not be the cause of the problem, it also gives me part numbers, check out the site look up your own model it may give you the answers
you can check out the main manuls or look up past technical bulletins (tsb)
good luck

SOURCE: 2002 Kia Rio runs rough when idling

well spend some change and have a simple tune-up.  Plugs and filters and readjust the idle.

SOURCE: 2002 kia sedona 3.5l has rough idle replaced plugs wires and coil

this vehicle has coil packs for the ignition correct? have you ran the engine at night with all surrounding lights outs so its really dark. spray a mist of water on the coil packs and spark plug wires to see if you have spark/voltage leaks jumping out from them. sometimes the tiny sparks will be so fine and skinny you can barely see them so it needs to be dark. hope this helps your trouble shooting. a coil pack could have such a fine crack for the voltage to leak from that you cant see it.

SOURCE: Kia sedona. Knocking sound from Engine

I assume by now you have this problem fixed, but if not, or for the benefit of others looking for help, try replacing the coil on the #5 cyl as well as the injector. Ours did same thing, except fault code was on #2 cyl, so I got the parts from local parts store for about $150 total, and completed the repairs myself on my wife's 2003 Sedona. Now i can start on the rear heater issues, the knocking sound coming from the LF tire area while in motion, and replacing all brake pads. 92,000 on the odo. I'll spend the extra $ and go with the Honda Odyssey next time.