Hey guys I'm looking at purchasing a 2001 Silverado 1500 Z71. A couple of things about the truck bother me. The check engine light, abs, and brake light are all on. I had the owner get the error codes diagnosed. Evidently the previous owner had gutted the catalytic converter, so I will need to get that replaced. How hard and expensive is it to replace this yourself? Also the ABS sensors are out so I will need to replace those as well. I know those run fairly cheap but how hard are they to replace? Also I was looking to get a leveling kit for it and was wondering what the better ones are and if it would be easier for me to do it or just get a professional to do it. Thanks!