Well, now i fully understand why i cannot use a b16/bigger tb on my y4. for traditional OBD2s, the IACV is on the rear of the manifold. However on the y4, the IACV is located on the tb at the bottom. so in order for a bigger tb, a new intake manifold must be used from a D16Y8 where the IACV is located at the rear.
What i would like to know is, can i use the y4s IACV on the Y8 manifold? or do i need the Y8 IACV aswell? i know the y4s IACV is 3-wire & y8s is 2-wire.