last month I bought my cobalt 2006 ss 2.0 on November 27th, till December mid-20s there was no issue, after when it got cold here in Toronto like minus 10 or minus 20 Celcius, the morning when I start the car starts perfectly I let it every time to warm up like the coolant temperature I wait till gets 35 Celcius, and all the sudden it shuts off even the car is getting warmer like even if its 35 Celcius or 80 Celcius the car shuts off and it says Engine Reduce Power/ engine disabled, and if I start it there is a crank and every time when it does it I have to boost it to start the car otherwise it won't start the car. so I thought the battery was the issue so 2 days ago I got a brand new battery from ACDelco 600 CCA, same specs that the car requires and today this morning it was minus 17 and the car shut off like 5 times on the road when I was going to work and my work is like 6 km 7 km away from my home, thank god I had the boost with me, today I checked the voltage while the car was running at the battery I was getting 14.9 volts, I checked my ground in the trunk it was clean like there is 0 corrosion even on battery terminals. and this problem only does when the weather gets colder, do you guys have any suggestions? I'm assuming there is an open circuit or something that draining the battery out, the car is fully stock and the car has 130k on it, it was 129k on it when I bought it, tomorrow my master tech and I will do a parasitic draw test and we have to see if there is any component that taking power from the battery while the car is turned off. if you guys have any ideas let me know I will be appreciated it.

 

Check all your grounds.

 

Is the check engine light not illuminated? Almost sounds like a MAF issue... other than it not happening during cold start.

Might still be worth having the codes read with a quality reader; sometimes there are codes sitting in the pending queue, but haven't hit enough cell counts to pop the light on.