thanks, i think i figured out the wiring, pin 1 is Orange/Dark Green, pin 2 is Violet/Orange, pin 3 is Black/Light Blue and pin 4 is Tan/White. The Black/Blue wire is sensor ground provided through the PCM. The Orange/Dark Green wire is power provided through the ASD relay. The Violet/Orange line is for the PWM (Pulse Width Modulated) heater circuit which also runs to the PCM. The Tan/White wire is the Signal Circuit that runs to the PCM, my truck is running much better after getting the oxygen sensor put in