How To Bypass O2 Sensor: The Expert Ways and Steps 

How to bypass O2 sensor? It’s easy; install a dummy O2 sensor or an oxygen sensor extender (adapter). The option you choose depends on your situation. 

Steps to Bypass O2 Sensor

We have detailed coverage of this and other informative details below for you. Read on to learn and resolve any O2 sensor issues like a Pro!

How Can You Bypass the O2 Sensor Like an Expert? 

To bypass the O2 sensor in front of the catalytic converter (cat), replace the original sensor with a dummy sensor. Suppose you want to bypass the sensor after the cat. In that case, you’ll need to use an adapter, otherwise known as an oxygen sensor extender.

An O2 (oxygen) sensor is a critical component of a car’s fuel and emission system. As its name suggests, the sensor monitors the amount of oxygen within the exhaust and conveys that information to the engine computer. 

The computer then utilizes this info to adjust the air and fuel mixture to the optimal ratio. If the O2 sensor malfunctions, the engine computer fails to set the air/fuel ratio correctly. That results in performance problems, including lower fuel economy and increased emissions. 

An incorrect air/fuel ratio can also cause damage to other critical components, such as overheated cats. At this point, the Check Engine Lamp/Light (CEL) will undoubtedly come on, which can be annoying. We will show you how to bypass O2 sensors using a dummy sensor (a fake O2 sensor that functions like a normal one) or an adapter to resolve the issue. 

To bypass the O2 sensor with a dummy oxygen sensor, follow the steps below, but first, gather these tools:

  • Dummy oxygen sensor 
  • Wrench or pair of pliers
  • Car jack
  • A set of screwdrivers
  • Oxygen sensor removal tool

– Disconnect the Battery

Allow the car to cool down before starting. The exhaust might take several hours to cool fully after a drive. Once it cools, open the hood and pull out the negative battery cable.

Use the wrench or a pair of pliers to loosen the nut and quickly slide the clamp off the terminal. 

– Jack up the Car

Jacking up the car will provide you with more space to work. So, use the front jack point to lift the vehicle.

Put the jack under the frame at the front and gently lower the car down on the stands. This will give you an easy access and speed up the process.

– Remove the O2 Sensor

Locate the oxygen sensor that needs to be removed; it should be the one before the catalytic converter. Using a set of screwdrivers, unscrew the wiring attached to the component.

Locate the Oxygen Sensor that Needs to Be Removed

Next, pull the sensor away from its housing by turning the tab anticlockwise with the help of a unique oxygen sensor removal tool. 

– Plug in the Dummy Sensor and Test It

Install the new O2 sensor (O2 sensor simulator) by turning the sensor clockwise. Screw the wiring back to the sensor and jack down the vehicle. 

Start the engine and allow it to idle for a moment. The dummy O2 sensor will trick the engine computer into believing everything is okay. Check to ensure that the engine light is no longer on. You may need to drive the vehicle for a short distance for the check engine light to turn off. 

Note: Sometimes, the engine computer can distinguish between an authentic and a fake oxygen sensor. When that happens, your car won’t get the correct air/fuel mixture; it will lose power and experience fuel inefficiency. It would be best to only look for a dummy O2 sensor designed for your particular car.

How to Bypass Oxygen Detector With an Oxygen Sensor Extender

To bypass oxygen detector with an oxygen sensor extender, you need to follow the below steps:

  • Get the car ready and remove the oxygen sensor.
  • Install the adapter between the oxygen sensor and the exhaust pipe.
  • Drive the car to test the result.

Suppose your cat’s efficiency falls below a particular threshold and can’t perform its job effectively. In that case, the rear O2 sensor detects fault by recording more oxygen levels. An oxygen sensor extender bypasses the original sensor by sensing less oxygen in the exhaust gas and tricking the engine computer into believing that your cat is functioning well. 

In other words, the oxygen sensor extender manipulates the O2 sensor to detect less oxygen in the exhaust pipe. It keeps the oxygen sensor cooler and minimizes the exhaust gas in contact with the sensor. The extension may help turn off the check engine light, but it’s a temporary solution. 

– Get Your Car Ready and Remove the Oxygen Sensor  

First, disconnect the battery by removing the cable from the negative terminal. Allow your car enough time to cool down if the engine is running. After that, jack up the car to get a safe space to work, as discussed above.

Using your unique oxygen sensor removal tool, take the O2 sensor out. Unlike the case above, you don’t need to pull out any wires. 

– Install the Adapter

Attach the O2 sensor extender between the oxygen sensor and the exhaust pipe. That will allow the oxygen to pass through the O2 sensor without returning an error to the engine computer. 

– Drive the Car

Jack down the car and reinstall the battery cables. Drive the vehicle to enable the ECU to set the value and send the data to the computer to inject the correct fuel ratio

Jack Down the Car and Reinstall the Battery Cables

Note: If your catalytic converter or oxygen sensor has failed, the right thing to do is to go for the necessary repairs. Installing an oxygen sensor extender should be your last option because it’s inefficient in minimizing the pollutant exhaust gasses. Your car will probably not pass the next emission test. 

How Can You Make Your Own Dummy O2 Sensor? 

To make your own dummy oxygen sensor, drill three holes into a 1/2-inch square piece of wood. Next, insert a short wire into each hole. Lastly, connect the first wire to +5V, the second to GND (Ground), and the third to an analog input pin. 

Buying a dummy oxygen detector can be challenging, especially for first-time buyers. Fortunately, you now know how to make a dummy O2 sensor

Note: Although the DIY dummy sensor can produce an acceptable oxygen sensor signal, it’s not a cure for the check engine light. The oxygen sensor is utilized for closed-loop control. And if the signal doesn’t change appropriately, the ECU will discover it’s a fake O2 sensor and return an error. 

How to Bypass 02 Sensor Heater Circuit?

To bypass the O2 sensor heater circuit, you need to remove the O2 sensor and check its wires. You’ll find two heater circuit wires connecting to the sensor. Place a resistor of equal resistance value with the sensor between these two wires. 

We will break it down into simple steps for you below. 

Modern cars’ O2 sensors come with a heater circuit, a component that helps to bring the sensor to its proper operating temperature quickly. It enables the sensor to send a voltage signal to the engine soon enough, enhancing performance.  

When this circuit malfunctions, the ECU will return a code and turn on the check engine light. Bypassing the oxygen sensor heater circuit allows you to clear the code for the heated oxygen sensor malfunctioning. It leads the engine computer to believe that the oxygen sensor is performing correctly. 

  • Let the car cool down

Since you’ll be working on the engine and exhaust, you should allow the car to cool down if the engine is running. It must be at room temperature for your safety. 

  • Pull out the oxygen sensor

Jack up the car. Next, use the oxygen sensor removal tool to remove the O2 sensor and identify the two wires of the heater circuit. 

  • Attach the resistor

Place the resistor between these two wires. The resistor must have the same resistance value as the oxygen sensor. Use a multimeter to check heater circuit resistance to know that of the oxygen sensor; it should be anywhere from 5 to 7 ohms. 

  • Solder the resistor

Solder the resistor to the positive and negative wires of the heater, then cover it with tape to ensure safety. Connect the resistor in any direction. 

  • Drive the car

Drive at a low speed to allow the ECM to receive the data from the O2 sensor. If the sensor works correctly, the resistor will signal the computer and hide the check engine light. That’s how to bypass the O2 sensor heater circuit

How To Delete O2 Sensors from ECM

Deleting or removing the oxygen sensors from the ECM requires reprogramming the ECU through the car’s OBD-II connector. It involves the use of a computer with the appropriate software. Oxygen sensor deletion (Lambda sensor delete) should only be left to professionals. 

Deleting or Removing the Oxygen Sensors from The ECM

Deleting the oxygen sensors from ECM is an essential engine tuning solution. It can help you enjoy better fuel economy and efficiency. O2 sensor deletion can also increase engine power and performance and ensure cleaner emissions. 

Most importantly, the O2 sensor deletion allows you not to worry anymore about the engine error codes and the annoying check engine lights on your dashboard. It can also save you money on repairs. 

How Can You Trick the Oxygen Sensor After Removing Cat?

Tricking the oxygen sensor after removing the cat is one thing you can’t do. Even if you tried, the ECM would still be looking for a clean burn on the sensor, and if it can’t find one, the check engine light will turn back on again. 

As mentioned, the ECM is programmed to adjust the fuel mixture based on the information from the front O2 sensor. It then confirms its readings by monitoring the rear sensor. If it can’t see a cleaned burn, it senses the cat isn’t working correctly or, in this case, missing. So, it turns the light on again. 

Tricking the ECM by generating a ‘false voltage’ doesn’t work. That’s because the ECM runs a self-test from time to time by temporarily hedging the mixture to monitor the reaction at the sensors to avoid malfunctions. The light will come on if it doesn’t see what it expects. 

How to trick O2 sensor after removing cat? As said, the best thing to do is to fix the problem affecting the cat or buy a new one. Any other thing is impractical and can even be illegal!

What Is an O2 Sensor Eliminator and How Does It Work? 

An O2 sensor eliminator is a component that is used to bypass the stock O2 sensor without triggering the associated F1 error code. The eliminator simulates the signal generated from the oxygen sensor under optimal air/fuel ratio conditions. It allows the engine to run under optimal conditions. 

For instance, if you remove the catalytic converter, install an aftermarket exhaust, or perform a similar modification on your motorbike, installing an oxygen sensor eliminator can boost your engine performance significantly. 

A good quality O2 sensor delete kit can help you improve engine performance in the low and mid RPMs. As mentioned, it can also help with oxygen sensor bypass.


Whether you want to know how to bypass the O2 sensor on dodge ram or any other vehicle, our article equips you with the information you need.

Here’s a recap:

  • You can easily bypass the O2 sensor in two methods; using a dummy oxygen sensor or an adapter.
  • A dummy sensor is an appropriate option in case of an oxygen sensor malfunctioning.
  • If you have a faulty catalytic converter, bypass the rear O2 sensor by using an adapter.
  • You can bypass the oxygen sensor heater circuit by attaching a resistor between the sensor and the catalytic converter.
  • Deleting the oxygen sensors from the ECM can offer many benefits, including a boost in engine performance.
  • You can’t trick the ECM after removing the cat; the best thing to do is to repair or replace it.

So, choose your appropriate method if you want to bypass the O2 sensor for whatever reason. Do it and eliminate that annoying check engine light as you prepare to fix the problem as soon as possible. 


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