This circuit uses one LM324 is a Quad Amplifier. this circuit uses 2 amps per O2 sensor, so it will work to adjust two O2 sensors. As in the photo above, the top half of the circuit board controls the #1 O2 sensor and the bottom half controls the #2 O2 sensor.

Well, you need the parts shown on the schematic, soldering iron, solder, wires, multi-meter, the usual stuff to build small electronic circuits.

Yes you will need to CUT the O2 sensor wire, so the wire from the O2 sensor connects to the input of the circuit and the output of the circuit connects to the ECU or ECM

The circuit needs to be adjusted to make sure that the Output Voltage is no more than 1 volt. Your oxygen sensor gives off a one volt or less signal. You will adjust this when you install under your dashboard. A $10 Mulitimeter helps in reading the voltage in millivolts. I velcroed the multimeter onto my dash for a few days while I dialed in the settings and watched the voltage.

Locate all the compontents :

Layout all the resistors first, gold sized bands to the center. Don't solder them in until you place the IC socket for U1 Start soldering in the resistors. Add the U! Quad Op Amp when the circuuit has cooled from soldering. You will have to make short jumper (22awg) wires from Pot 1a and 1b from underneath the board to the dual stero pots. VR1 and VR2.

Below shows you how to hook up one of the IK pots in stero or dual mode for 2 sensors with the same siganl control.