So, last night it got extra cold for Arizona, around 40 farenheit (sp). When I left for work this morning, I let the car warm up for 3 minutes or so before I left, then after I pulled out and to a stop light, my idle was at about 1700, and then it would drop down to 900ish, then back up.

It continued to go back and forth about half of the way to work (6-8) minutes, then stopped completely, isn't doing it anymore.

I did search for the problem but all I found pertained to the problem not going away after fully warm.

Thanks in advance for any help or advice

 

Sounds like your Idle Air Control Valve (IACV). Its located on the back of your intake manifold. You can try removing it and cleaning it out with some Carb Cleaner. It might work as a permanent solution and it might not. If the problem persists, you're going to need to buy a new one which goes for I believe around $160 through the dealer.