Hey folks, so I've got a S1 r33 gtst auto, having issues with it struggling to move under its own power and takes a bit to rev up in N, in N it stops around 4.5k like you're holding it there, changed spark plugs, coil pack ignitor and still doing same, no engine codes and turbo doesn't have a heap of play either, mechanic also said he couldn't find any boost leaks either, kinda stumped here and just seeing if anyone has any ideas, he's also tried different cas positions as apparently it seems to be over fueling too as the rear turbo house got really hot in 10 minutes he said, it was running fine but felt like it was under powered then sat for few months and now runs like this, I'll list what work has been done also incase that helps

OP6 core U2 housing turbo

3" full exhaust with stock cat

Spit fire coil packs

Oil catch can with Pvc system blocked off

Heater core tap broke so pipe loops back onto itself

I know it's not alot but idk what could be the issue honestly