99 jimmy p0452 p0463 codes

I have a 99 jimmy 4x4 that sat for about a year. The motor threw a rod and rather then fixing it I replaced the motor. Now the service engine light is on and the abs light is on. I had a bad caliber on the brakes and changed it out. The low fuel light is on and the gas guage reads empty. I checked all the wiring and everything looked in order but I don't know if I am overlooking something or something might have got pinched in the process. I was hoping someone on here had an idea of what I could check or what. I am going to sell the truck but I hate to sell it like that.