why change maf along with pcm?

[DaviDawg]

why do you have to change the maf if youre changing from a 98 pcm to a 99.5+ pcm? im asking because the wiring seems to be relatively the same between the two. heres the wiring diagram for the 4 anf 6 wire maf. if i got a 99.5+ pcm couldnt i simply keep the iat seperate from the maf. what am i missing?
http://i298.photobucket.com/albums/mm254/davidawg/DSC00671.jpg

[iceracer]

On the '98 the IAT is seperate. The later ones have the the IAT incorporated in the MAF hence the two extra wires.

[DaviDawg]

huh, i still dont get it. instead of replacing the maf, why not just keep the 98 maf.

[tre2000zx2]

iirc its ta difference in the voltage readings of the 2 setups..

[DaviDawg]

thank you. that was all i needed to hear.

[ZX2Fast]

They have a slightly different calabration. But, I would rather keep the separate IAT.

[DaviDawg]

are you saying that you can change to a later pcm and keep the stock maf set up on an earlier zx2?