You won't need the reg, a Walbro in tank pump will be fine.
When you say stock boost what do you mean? 1zz injectors will fit the 1gfe and are an upgrade.
Basically when you full throttle the bypass hits a mechanical stop and if the cables too tight it then pulls on the normal throttle body causing the code and limp mode.
Its under the inlet manifold towards the front, but i wouldnt use one of them adapters, heard of them just snapping off under vibration and allowing all the oil out