In Az. I have heard alot of people say you do NOT need a muffler on a diesel truck. I have heard some say you do, I looked up the state laws and my brain can't take all the crap they have to read through. There are like 10,000,000 laws. Any of you that can help, anyone passed w/o a muffler, anyone been turned down because of no muffler? I allready cut it out and welded in a straight piece, but at some point I'll have to go through emissions.