went to autozone today i had p0171 and p0174 codes. i checked all the vacuum line for leaks and my air intake to make sure nothing is loose. my MAF was cleaned 6k miles ago (but im going to clean it again) i searched around and it seems that guys in northern states have this problem when it is cold out. it also idol's rough like it has a big cam in it until it warms up. this is my first winter with the truck, but from what i have read there are different style intake manifold gaskets and mine is the old one causing these issues? could somone please give me the part number for the right gasket. i also plan on doing the knock sensors while im down there and replacing the harness. also would this hurt my gas mileage? because it has been crap lately and im not even driving like a pissed of teenager.