if i convert to obd1 using the adapter harness from rywire.com do i need the vtec sub harness......right now i have a jdm b16 with a pw0 ecu that is already wired for vtec...so would i need this sub harness??

 

You could splice your current OBD0 subharness into the pigtail that extends from the ECU jumper
Note that you'll be using a 4-wire 02 sensor now, you'll be adding wires for that and eliminating your primary/secondary 02 sensors from the front of the exhaust manifold. You'll be running that 4-wire O2 right before the Cat'.
If you're comfortable soldering and connecting your own sensors, then you could DIY.
We made this package for people that just don't want the hassle. It comes with the subharness to be plug and play with that engine and it's new sensors. You will need the Dizzy jumper as well.