Login Form

Google Ad

Support / Knowledge

O2 Simulator w/ heater simulator

Pin It

Install o2 simulator AND create heater circuit simulator.

Tools required:
Side cutters
Wire strippers
Electrical tape
Spool of wire
Soldering gun and Solder


Parts needed:

o2 simulator ( www.o2simulator.com )
Old o2 sensor (for this built)
Correct resistor (two in this case)

Step 1

Cut connector plug off the old o2 sensor. Since o2 sensors are quite expensive I used one that was no longer good. If you are sure you are never going to need your secondary o2 sensor again then be my guest and cut away. Though, do cut wisely. Leave at least 2 inches of wire on the connector, you never know if you might make a mistake.. or two.

Step 2
The resistors

On most import cars the ECU monitors both the sensor side and heater side of the o2 sensor. If you want to completely remove the o2 sensor, simulators are needed for both. The correct resistor will take the place of the heater side of the o2 sensor circuit. On most Hondas the ECU is looking for a resistance range of around 10 - 40 ohms. In this case I am using 2, 10ohm 10watt resistors wired in series. Make sure in any case you use a high enough wattage resistor or it will burn up, 20watts or better should be fine.

After soldering the resistors together I tucked the wires between them and folded them together to make everything nice and neat. Next I soldered wires to the remaining ends and wrapped the assembly in electrical tape. A heat shrink tube could also be used.
I tested the resistors to make sure that all the connections were made. The result for this setup should be 20ohms with 5% tolerance on these resistors. A single resistor may also be used if it falls between the 10 - 40 ohm range that the ECU is looking for. I decided on 20 ohms because the original o2 sensor came out to be 13.6 ohms. I wanted something as close to that mark as I could get.

Step 3
Wiring in the resistors and o2 simulator

I chose to use an old o2 sensor harness plug to make everything neat however everything may also be wired directly to the cars wiring harness. For Honda 96 - 00 the harness colors are as follows: White/Red-Sensor wire, Green/Yellow-Sensor ground, and Black/Yellow-+12v heater. If you plan to use the o2 sensor plug such as I did, the picture shows the polarity of the two black heater wires that are attached to the stock o2 sensor.

Although the resistor can be wired in either direction, +12 volts is needed for the o2 simulator and this is the easiest place to get it, as the next few steps will show.

Note that o2 sensors that ARE NOT oem will probably have different colors for their wires. Follow this diagram.

The o2 simulator

First I wired up the o2 simulator to the + and - signal wires. Green is negative signal and white is positive signal. This is equal to black and white on the o2 simulator. The red wire is the +12v power wire for the o2 simulator and will need to be hooked to the +12v heater circuit wire as shown in the previous picture.

The resistors and power wire

This picture shows the complete wiring. The resistors are wired into the heater circuit along with the +12volt o2 sim power wire that goes to the +12volt side of the heater circuit. The reason I used crimp connectors for this and not solder is because the wires on the o2 sensor are heat resistant and are impossible to solder to. It just doesn't stick.

The finished product

The resistor pack will generate some heat, though not enough to burn through anything I would suggest putting it somewhere out of the way. Do not tape it to the o2 simulator. If you have any questions feel free to post them in the support forum of this web page.