Hello! I've done some researching on this forum in the last week but this is my first post. I recently picked up a 2017 R1. Previous owner did some mods that I'm trying to figure out whether to keep them or not and would appreciate some feedback It came with a mystery mid pipe and mystery muffler installed. He also included the Akrapovic GP slip-on. I want the Akra so I tried to install it on the mystery mid-pipe but it was a no go. It was also very loud with the mystery mid pipe and mystery muffler with no DB killer. I need it quieter to run at tracks. I have ordered a stock cat from ebay and plan to use that with the Akra muffler. The bike also has a PC5 installed and the EXUP delete servo plug thing. I'm wondering about the tuning once i get the stock cat and akra slip-on installed. I don't want to get the bike dyno tuned at this point. Do i need to get the EXUP back on? I have the motor and cables so thinking it will be possible, will just take some figuring and maybe shopping for some bolts and such. My understanding is that the EXUP defaults to the closed position so seems necessary to have it all hooked up. Perhaps there is a way to keep it open or remove the valve like i was seeing mentioned in some other forums when i was doing some searching. I think I would prefer to keep the EXUP deleted. I'm assuming i can use a map for the stock exhaust setup on the PC if i reinstall the cat but not sure if the EXUP removal will work with a stock map or just the stock ECU itself with the PC. That's my main question at this point. Also, is the PC even necessary with the stock cat or should I sell that thing and pocket some cash? Seems it might be necessary if the EXUP is deleted? I can't find a forum post confirming this. I also haven't seen a map for that. I only see maps for stock setup (which I assume means EXUP installed and functioning) or for full exhaust. I may in the future get the proper Akra mid-pipe and the DB killer and maybe that will be OK in which case it would make sense to keep the PC. I just really don't want to go down the tuning rabbit hole at this point. I'll post up a picture of the bike once I get this exhaust mess sorted. Sunshine is also rare this time of year here. Thanks for any feedback you guys can provide!