New to forum and never used HP tuners before. The story goes my brother bought a twin turbo 2014 mustang 5.0 and it makes insane power and runs great during the summer. It was tuned with HP tuners and he as a labtop and the interface that came with it. We live in Minnesota and yesterday it was in the 30's and it started and ran fine. It was only started to make sure it would start if we rented a trailer for Sat. So we rented the trailer. We of course don't drive hot rods in the winter but today we wanted to move it to my shop an hour away to do some work over the winter. We went to start it to put it into an enclosed trailer and it was a nightmare to say the least. It has bigger injectors in it and stuff and I'm guessing whoever tuned it didn't tune it for the bigger injectors in the cold weather, I'm not sure. It was 4 degrees today and when we did get it to start it was with the fuel pump unhooked and then turn it on once it was running and try and keep it running. Once it was running the AFR was 9.0:1 and fuel was running out of exhaust and it didn't have enough power to move out of its own way and if you let it idle it was so rich it died. I pulled up HP tuners on his computer but I have literally never touched it before so had no idea what to do? We unhooked the MAF and IAT and got it to run, still idled at 9.0:1 but as soon as you touched the gas it was 20:1, so as you can see it took use about 3 hours to get it in the trailer, that shoulda taken about 2 minutes. It runs great in the summer and drives fine and came with dyno charts something to the tune of 863 rwhp, but can anyone tell me what I need to do change to make it run when its in the minnesota winter, it doesn't need to be perfect just start and run and drive itself in and out of a trailer as in minnesota from November- April our stuff pretty much stays in a shed.