I'd keep the DOC and the muffler, if you altered the exhaust. DOC sweetens the smell, muff....well, I like quietness running 75-80 for hours on end....not that I'm advocating a delete.
Several years ago, the normal shop I had been swingin' by for years, were all backed up. So, I went across the street to an exclusive Inspect only shop.
Not knowing the personnel, when the guy came out to go test the brakes, I kind of jokingly said, "careful, that throttle's a bit touchy!"
Didn't like the look I got. After the stop check, he pulls into the bay for the rest of the inspect. Last thing he did was to walk down the pass side with a large Border Patrol style mirror on a stick, viewing the underside from end to end.
I asked, "what are ya lookin' for?" (exhaust is original)
Lying prick said he was checking the exhaust mounts for wear....
You can't see the rubbers' conditions with a mirror on the bottom side.
I haven't been back....hate being lied to.
On the other end of the scale, the place I happened upon out on the road, back a few months ago for an inspect.....saw it was a Diesel and never even touched the truck on their way to the PC.
2007 LBZ 3500 LT3 DRW Crew Cab, Sulastics, Putnam XDR 15K, B&W 30K-Turnover GN+Companion, Ride-Rite Air...EFI'd by Rob
2008 LMM 3500WT DRW Crew Cab, 8 'Flat/GN, Workforce Alum Toolbox, Ride-Rite Air Use-ta Haves 2006-6.0 3500 WT DRW ExCab Flatbed, 2005-LLY 3500 LS DRW Crew Cab, 2002-LB7 3500 LS DRW Crew Cab I Live my life in such a way that when my feet hit the floor in the morning...Satan shudders & says "Oh shit, he's awake!"