O2 Sensor Bypass

Tired of getting those pesky CELs because you don't have a catalytic converter or your 2nd O2 sensor is failing?
Here are the steps to follow to eliminate the sensor entirely.

  1. The first part is to eliminate the actual sensor part of the O2 sensor.

    This is how our circuit will more or less be, note that we won't have the O2 sensor at all anymore. Here's our schematic:

  2. Take the 1Mohm (that's 1,000,000 ohms) and the 1F (micro-farad) capacitor and solder the two together in parallel.
  3. Remove the front seat from your car and detach the two O2 sensor harnesses from each other.  You want to work on the harness side that is attached to the O2 sensor (it's easiest). Cut all 4 wires leaving about 2.5-3" of wire. You should now be able to remove the harness piece from the car.
  4. Strip -" of insulation off of the blue and white wires. Solder your two components onto the blue and white wires.
  5. Tape/heatshrink everything up and make sure that nothing is shorting against anything else.
  6. Now we'll eliminate the heater element of the circuit. You'll need a resistor of ~12 Ohms. This heater element flows around 1 Amp of current so you'll need resistors that can dissipate at least 12 Watts of current. Don't scrimp here as under-rated resistors could set your car on fire.
  7. Strip the two black wires, solder the resistor in between the two wires. Tape/heatshrink everything well.
  8. Plug the harness back into the other ECU side of the harness and put your seat back in.

That's it, you're done!