K03s turbo on agu

[Ant b]

Hello following on from my other thread about my friends turbo/oil pressure problem Hes just had a ko3s turbo fitted to his agu(ko3) and the mechanic just rang and said it feels sluggish to how it was before.it was mapped before and I know to get the full benefits from the ko3s it needs mapping again but I thought it would be as fast for now.he said he unplugged the n75 and made no difference also has no lights and he's scanned it.
My freind just wants the car back now it's been months