My car starts to die out in cold weather. its when i'm not giving it gas the rpm start to go below 1 and i start to lose everyting but once i give it some more gas it starts to work again. this happens when i'm driving to slow down and especially if i'm going down a hill. I have put deicer in but thats not helping. It has close to 4 hundred thousand kilometers on it. Could this be a map sincer, plugs. please help.