skip to content

How to Bypass O2 Sensor (2023): 80% People Don’t Know

Every car is equipped with several sensors, and the O2 sensor is one of them. If you check the engine light and notice it has been flickering for the last few days, it may be a time bypass O2 Sensor. Cars generally have a couple of O2 sensors, with each measuring differently. This article will focus on the economic and easiest ways on how to bypass the O2 sensors.

But before that, let’s quickly check out the various reasons why one need to Bypass oxygen sensors:

  • In the absence of a catalytic converter, bypassing the O2 sensor to avoid the constant flickering of the engine light becomes essential.
  • To tune the engine when you are into off-road racing.
  • To revoke the casual system errors.

What are the Reasons for the Failure of O2 Sensors?

Over time as you drive your car, it attracts more and more dirt and debris. It leads to excess oil coagulants and fails the system.

What are the Symptoms of a Faulty O2 Sensor?

Here are some common symptoms of a faulty O2 sensor:

  • Indication by code checker
  • failure in the emission system test
  • check engine light is constantly on
  • Rought idling, degrading performance
  • Reduced fuel mileage

Ways to Bypass Oxygen/O2 Sensor:

Dummy Oxygen Sensor

It would help if you had a dummy oxygen sensor when removing your catalytic converter, which is illegal. Hence finding it can be challenging for you.

All you need is to locate the O2 sensor in your car and replace it with the dummy one. The dummy sensor you are going to plug in must be programmed as per your vehicle.

Otherwise, your car will lose fuel and power efficiency gradually. It will not get the proper fuel mixtures and may cause issues with your vehicle.

Step By Step Guide on How to bypass Oxygen/ O2 sensor

Step 1: Let your car cool down completely as the hot engine may lead to hand burn. If you just drove the car, wait for at least 6 hours to let all the components cool down, including the exhaust systems and engine.

If you live in colder regions, you may expect the car to cool down completely in under 4 hours. But, if you are living in hot climatic zones, it may take longer for the vehicle to cool down.

Step 2: Once you are assured that the car has been cooled down completely, locate the negative battery terminal to disable the cable. You have to loosen up the nuts fixed on its cable clamp.

Step 3: Use Jack stands to raise your car from the front. Place the front jack point at the rear of the radiator underneath the front pinch welds and lift the vehicle to a considerable height so that you can work comfortably.

Step 4: Situate the jack point under the front pitch welds and lower the car slowly on these jack stands.

Step 5: Find the Oxygen/ O2 sensors that resemble a plunge protruding out of the engine exhaust system. You can find them at the rear and end of the catalytic converters easily.

Step 6: Look for the wire embedded within the sensor to unhinge. To release it, you have to squeeze it gently. Now pull it out carefully from the O2 Sensor’s housing.

Step 7: Now rotate the sensor in an anticlockwise position to remove it. You can also take the help of a removal tool.

Step 8: Now install the dummy O2 sensor in place of the replaced oxygen sensor by turning it clockwise. Fix it into the electrical houses and connect it with the electrical wiring.

Step 9: time to lower the car using the same jack you used to lift it.

Step 10: Start the engine once the wheels are properly put down on the ground to check the engine light.

Step 11: If you find the lights to remain on, drive the vehicle gently to check if they turn off after some time. It is to complete the cycle that your vehicle’s computer system perceived with the sensor in place.

Step 12: Once this cycle is complete, you can bypass the O2 sensor successfully.

O2 Stimulator

O2 stimulator is an alternative to a dummy O2 sensor. An Oxygen sensor sends the proper wavelength signal to the computer. However, the wavelength is just one of the working parameters of the oxygen sensor. These sensors work with capacitors and resistors.

It would help if you bought a high-quality O2 stimulator; else it will not work.

Other Alternatives

If your car is not compatible with an O2 simulator or dummy sensor, other alternatives are available to rescue. The resistor is one of the considered alternatives. As your sensor is already compatible with your vehicle, attaching the resistor straight with it works well.

The process of attaching the resistor is the same as above. Remove the O2 sensor and solder resistors on its connector. Now plug in the O2 sensor with a resistor on it.

These methods are for the second sensor, which is after the catalytic converter and not for the pre-catalytic convertor.

Messing with the pre-catalytic converter O2 Sensor can reduce your vehicle efficiency drastically. It is responsible for controlling the fuel mixture in the engine. However, changing the second sensor will not.

Frequently Asked Questions

What is an Oxygen/O2 sensor?

The sensors are part of the exhaust system. They detect the amount of oxygen remaining in exhaust gas to estimate efficiency, fuel mixture and produce critical data for further calculations.

Why do I have to bypass my O2 sensor?

If you want to tune your engine without letting your system throw an error, you have to bypass the O2 sensor.

How do I know if my O2 sensor is working properly?

It is hard to check the performance of Oxygen sensors in cars. However, if it is non-functional, you will see an engine light on with time delay in acceleration or decrease in fuel efficiency. So when your engine light is on, it is the right time to replace it.

Is it Advisable to Disconnect O2?

No! Never disconnect O2 as it may have serious consequences of the substantial crisis in the engine. Oxygen sensors are responsible for a mixture of air fuel.

Is it ok to Delete the O2 Sensor?

To ensure that the exhaust system works fine, you have to connect a plug into the O2 sensor after deleting it. It will ensure that the gasses are escaping from the pipes efficiently.

How much will it cost me to bypass the O2 sensor?

Ideally, it cost around $100-$200. It also depends on location, the mechanic you are dealing with and your choice of replacement. If you are doing this yourself, you can even save money.


The only reason for bypassing the Oxygen sensor is to avoid the engine light on. If this doesn’t make any difference to you, you don’t require to bypass the second sensor.

YOu should check the engine light is recommended to locate any issue with your vehicle. The OBD2 scanner is also useful in clearing your engine light. But it may re-blink again.

This comprehensive guide on bypassing the oxygen sensor is insightful if you are looking for a reliable solution to keep your engine light off from flickering. The only caution is to work out on the second sensor and check the compatibility of the alternatives you consider switching with this sensor.

Website | + posts

My Name is Christopher Angels, and I am a postgraduate in mechanical engineering. Cars have always excited me as a child, and soon I decided to dive into the world of cars by pursuing mechanical engineering. I also worked as a Mechanic for over 3 years to understand Cars' anatomy and how each part contributes to its working.

Leave a Comment