So, with it being -40*C here for a while, i had a code come up with my truck, so when i was letting my truck warm up, and i read the codes, it was a knock sensor code, which i knew i had to replace, and i have everything to replace it with, so i just cleared the codes, WITH THE TRUCK RUNNING, and after that, my airbag light decided to come up and stay illuminated.

What can i do to stop it from being lit up?

And second, i just re-geared my truck from 3.73, to 4.56, and i went into my tune and changed my gears and tire size to match. 35" tires, and 4.56 gears. Now every time i hit a large bump, or go over rough train tracks, my ABS light comes up, and stays lit up until i turn my truck off, then when i start my truck, it is still illuminated until i drive it for a little bit and then it goes off again, UNTIL i hit another bump or train tracks...

What could i do to stop this?