Is the check engine light related to the electrical system?

Hi there,

I changed the headlight in my wife's Kia. To do so I had to
remove the battery as it was blocking access to the
headlight.

I replaced the battery but I dont think I tightened the
terminals enough as the car stalled. It was difficult to start
again, but after a few minutes and a few attempts it
started.

I got it home and tightened the terminals up. It seems to be
starting well and it's not stalling. Although I'm scared to
take it out for a drive again. However, now the check engine
light is on and I don't know if it was on before. I plan on
taking it to the garage to have it checked but in the
meantime I'd like to know if the two issues could be related,
for piece of mind.

The only additional information I have is the voltage
between the battery terminals. 13V when off and 14V when
on. So it seems to be in working order.

Any information would be much appreciated.