Community Member Credit: Sdot82 / tatanko

As of right now, there are primarily eight different ways to do this swap. Each has its own advantages and disadvantages, which will be discussed. They are as follows:

1) -00 upper manifold
-00 lower manifold
-00 fuel rail*
-00 injectors*
-00 throttlebody
-00 IACV
-00 EGR guide tube**
-00 rear valve cover***
-00 rear coil packs***

»Pros: Probably the least amount of work/customizing (and if you can find it all on one car, the easiest to compile parts for/possibly cheapest), throttlebody doesn’t require block-off.
»Cons: Requires tuning due to larger injectors, requires work to adapt the fuel rail to the old lines, the 00 IACV is iffy at best on the 4th gen ECU.

2) -00 upper manifold
-00 lower manifold
-00 fuel rail*
-00 injectors*
-00 throttlebody (requires block-off plate in this setup)
-4th gen IACV (needs adaptor plate)
-00 EGR guide tube**
-00 rear valve cover***
-00 rear coil packs***

»Pros: Second least amount of work/customizing (and if you can find most of it on one car, easier to compile parts for/cheaper), possibly superior IACV setup (not proven), throttlebody needs block-off plate.
»Cons: Requires tuning due to larger injectors, requires work to adapt the fuel rail to the old lines, IACV needs adapter plate, throttlebody needs a block-off plate.

3) -00 upper manifold
-00 lower manifold
-00 fuel rail*
-00 injectors*
-Pathfinder throttlebody (needs adaptor plate)
-4th gen IACV (needs adaptor plate)
-00 EGR guide tube**
-00 rear valve cover***
-00 rear coil packs***

»Pros: Lesser amount of work/customizing (and if you can find most of it on one car, easier to compile parts for/cheaper), possibly superior IACV setup (not proven), larger throttlebody, throttlebody doesn’t require block-off.
»Cons: Requires tuning due to larger injectors, requires work to adapt the fuel rail to the old lines, IACV needs adapter plate, throttlebody needs adapter plate.

4) -00 upper manifold
-00 lower manifold
-00 fuel rail*
-00 injectors*
-4th gen throttlebody (needs adaptor plate)
-4th gen IACV (needs adaptor plate)
-00 EGR guide tube**
-00 rear valve cover***
-00 rear coil packs***

»Pros: Lesser amount of work/customizing (and if you can find most of it on one car, easier to compile parts for/cheaper), possibly superior IACV setup (not proven), throttlebody doesn’t require block-off.
»Cons: Requires tuning due to larger injectors, requires work to adapt the fuel rail to the old lines, IACV needs adapter plate, throttlebody needs adapter plate.

5) -00 upper manifold
-4th gen lower manifold****
-4th gen fuel rail
-4th gen injectors
-00 throttlebody
-00 IACV
-00 EGR guide tube**
-00 rear valve cover***
-00 rear coil packs***

»Pros: Doesn’t require tuning, throttlebody doesn’t require block-off.
»Cons: IACV needs adapter plate, IACV is iffy at best on 4th gen ECU, lower manifold must be drilled.

6) -00 upper manifold
-4th gen lower manifold****
-4th gen fuel rail
-4th gen injectors
-4th gen throttlebody (needs adaptor plate)
-4th gen IACV (needs adaptor plate)
-00 EGR guide tube**
-00 rear valve cover***
-00 rear coil packs***

»Pros: Doesn’t require tuning, possibly superior IACV setup (not proven), throttlebody doesn’t require block-off.
»Cons: IACV needs adapter plate, lower manifold must be drilled, throttlebody needs adapter plate.

7) -00 upper manifold
-4th gen lower manifold****
-4th gen fuel rail
-4th gen injectors
-00 throttlebody (requires block-off plate in this setup)
-4th gen IACV (needs adaptor plate)
-00 EGR guide tube**
-00 rear valve cover***
-00 rear coil packs***

»Pros: Doesn’t require tuning, possibly superior IACV setup (not proven).
»Cons: IACV needs adapter plate, lower manifold must be drilled, throttlebody must have a block-off plate.

8) -00 upper manifold
-4th gen lower manifold****
-4th gen fuel rail
-4th gen injectors
-Pathfinder throttlebody (needs adaptor plate)
-4th gen IACV (needs adaptor plate)
-00 EGR guide tube**
-00 rear valve cover***
-00 rear coil packs***

»Pros: Doesn’t require tuning, possibly superior IACV setup (not proven), larger throttlebody.
»Cons: IACV needs adapter plate, lower manifold must be drilled, throttlebody needs adapter plate.

* = can be substituted for 01 QX4 parts, ** = can be removed and replaced with block-off plate, *** = you can grind down the rear coil packs and coil pack bosses instead of using these parts, **** = use of 4th gen lower manifold requires that you turn it 180º