simpsonracing

Ok boys i need your help. i have an emmision / fuel problem and i know its gonna be easy i just wanna make sure im on the same page as everyone. 1999 Burb with 130K miles on it and sulfer smell so i can guarantee the Cat is going out. My Question is should i ditch the Cat and str8 pipe it cause i live in Az and we have no emmissions or put a mufler in place of it. It already has a Magnaflow Mufler on already in place of the origional. I just dont want it to loud. The truck is getting lazy at stop lights when it idles too long and it will raise and lower idle speeds when at lights when i have to make a quick stop. I think the fuel pump is going out cause when it sits for too long it cranks over a little more than a few times before it starts. Would a Fuel pump be causing all of this or is it the multipul of items that i am suggesting. Ive changed the cap rotor plugs and wires in the last month so i know its not that. When it idles rough at a stop it also tries to diesel like its out of time. But i know its cause it idles from like 800 rpm to like 300 rpm. Any suggestions would be much appreciated.