Yeah, Neo 4 chips suck, you have to cut a track and remove a resistor to install them. I have never fooled with Neo4 chips myself, to many wires for so little performance, nor do i know anyone that has upgraded from one. As far as i know you must repair the cut track and resistor shown in the install instructions here:
www.psxgirl.com/sbox/neo4_instruct5.htmAgain, I have never done this. If Spedmetal, Hull_chipper or Dust2dust dont reply with any ideas you may want to contact "Shadowknyght". He is in australia, maybe he can help