2010 Kia Rio cranks but will not start. After it would set for a day it would start,

When I would try to start it it would crank and crank and nothing. I have
replaced most of the sensors the o2s , crank,idle, don’t know what else is left
to replace that would relate to this problem. It gets fuel be cause I smell it
when it’s cranking.when I do get it to start I drive it for a while without shutting
it off , and come back home. I would do this a day or so then it will not start
again.I knew about the time I got belt, so I had it replaced at about 66000
mi..be for. That I would get check engine lights, hence the replacement of the
sensors began, now it’s the start when it wants to ...as of now it hasn’t started
in over two months. all fuses are ok, the belt was put in at the dealership,
Could it be a wire harness problem,and if so is it easy to replace?  I. Would
love to get this worked out.....thank you can help