3 wire 02 sensor question

[Astroblaster]

I am planning on converting the single wire 02 sensor on my 1989 to the 3 wire 02 sensor. What would the best way to wire this.Would I need a 4 prong 40 amp relay.Sorry I am not too smart on electrical stuff....Thanks

[SoCalli V8]

It`s much easier than that, you are gonna have two white wires for the heater inside the oxy sensor and one black wire which is the signal wire to the ecm. You need 12volts fused (10-15amp) switched on by the ignition switch and ground for the two white wires (it doesn`t matter what way round) and the black wire connects to your original signal wire. Solder all connections.