I am installing a ngk powerdex in my 95' running a mspnp. The powerdex only requires 3 connections: power, ground, and signal to ecu. The stock 4 wire plug has signal, ground, and 2 +12v heater wires. If anyone is wondering why I would like to wire it this way its because I can centralize and simplify the wideband harness to a single connection rather than a one wire going over there and another over there. I don't know if its cool to use the switched +12v leads this way and if the ground is suitable. It would be nice to do it this way but will it work?

 

Its done. Wired the power and ground near the radio. works fine. The afx sucks due to the bulk of the harness and size of controller. regret not getting the lc-1, unfortunately it went on sale like 2 days after I bought the powerdex.