i drive a early 07 and i recently pulled my 7000 lbs rv from phoenix to amarillo. i ran my smarty on level 3 and drove 70 to 75 mph and taking it easy up hills watching my egts. well since i have been here in tx i have only started it a couple days a week and the first start of the day it idles a little rough, still at 800 rpm but its just a little rough. it does smooth out after a couple minutes, so just wondering if its an injector, or just what. i will say the low in amarillo is low 60s and in phx it was low 90s right now. anything helps