Well Akrapovic does advertise on their website that all their performance graphs are with stock ECU mapping and it won't hurt anything to run it that way but of course they recommend a piggyback fuel control for best performance.
BTW, I dropped the Yoshi RS-5 off the CBR this morning and then dropped it into the nearest trash dumpster. I'm not kidding, I could not sell it to someone else with a clear conscience so I ate the whole $900 enchilada......burp.... it didn't taste to good either.
I contacted Yoshimura three times and sent photographs and verbal description of the issue but they are not responding. They won't get any more of my money. #2 gasket was almost burned in two due to a bad exhaust leak, as suspected, the flange was not square with the face of the #2 exhaust port. #1 had the same problem but to a lesser degree and appeared to be sealing OK. #3 and #4 were almost perfect seals.
I cleaned up the carbon residue around #2 with scotchbrite and it came off revealing no damage to the stud boss or exhaust port sealing surface on the cylinder head. Looks like I dodged the bullet this time.
Stock header is back on now and I'll install teh Akra slipon and reprogram the PCIII later this day if all goes well.
I'm just going to write this whole thing off as a bad experience.
2021 Aprilia RSV4
2020 BMW S1000RR
2016 ZX-10R KRT
2016 959 Panigale Red
2015 CBR1000RR SP Repsol
2011 ZX-10R Ebony
2009 ZX-6R Lime Green
2006 ZX-14 Red
2004 VTX 1300C Candy Red
"For we walk by faith and not by sight" II Corinthians 5:7