Homework Help: Car engines

im wondering what reaction would likely occur
2NO (g) → N2(g) + O2(g) or the reverse

2CO (g) + O2(g) → 2CO2 (g) or the reverse

well the first one would occur if it were the reverse because of the high temperatures in the engine, but im wondering about carbon monoxide, what do you guys think

 

wait a minute, All internal combustion engines depend on the exothermic chemical process of combustion
so therefore these are more likely to occure the way i wrote them

 

i did, and the ones i wrote are both spontaneous, but the reverse are endothermic