My old Caravan seems to be real sensitive to the outside temperature. In the summer it runs like crap, and then gets better as we head into fall. Now with the temps down around freezing, my check engine light is on, and my gas mileage has dropped. I suspect that the brainbox is getting a wrong reading from what ever senses the intake air temp. I can't seem to find in my Haynes any info on that sensor. Can anybody point me in the right direction?