I have a 2015 Chevy Trax. This thing, when warm, runs amazing, but when cold, horrible. The colder the worse it runs. Backfiring, sputtering, stalling, etc. After driving about 6 blocks, it comes back to life. My wife tried to take our boy to school this morning and it stalled 6 times leaving the driveway and for the 1st time, it was -4 F out, it just died while driving down the road. She came back and grabbed my truck to take him to school. I've replaced the MAF, coil to spark plug boots and electrodes which I have to do every 4 months since buying this thing, all O2 sensors, etc. The codes only show misfiring and such which of course they will. I am at a total loss. Short of the catalytic convertor, I think I have replaced everything possible. It is undriveable in the cold but she needs to drive an hour one way to work each day. Any thoughts?