An O2 sensor monitors the exhaust flow to send indications to ECU to adjust fueling. But, this sensor could be responsible for turning in the check engine light in the vehicle. In this case, using an oxygen sensor spacer will resolve this issue.
So, what do O2 sensor spacers do?
The spacer is placed on the O2 sensor downstream. There is no fuel mixture control with this sensor. The purpose of this device is to monitor the health of the cat.
Post-cat oxygen sensor readings are compared with pre-cat oxygen sensor readings. The cat efficacy error occurs if there isn’t enough drop between the two.
Accordingly, the post-cat O2 should be leaner than the pre-cat O2. The spacer corrects the error.
Mainly, oxygen sensor spacers pull the oxygen sensor out from the exhaust pipe. As a result, the increased oxygen level in the exhaust flow can’t manipulate the oxygen sensor. Thus, the ECU keeps thinking everything is alright with the cat system.
In this article, we will discuss the functions of O2 sensor spacers and how to install them in the exhaust system. Therefore, stay with us till the end of this article.
What Do O2 Sensor Spacers Do?
The primary function of oxygen sensor spacers is to close the open loop and solve the check engine light flashing issue. Here, we are going to discuss some other functions of the O2 sensor spacer:
Takes Out The Oxygen Sensor
The spacer will take out the oxygen sensor from the exhaust pipe. Thus, the sensor will not be able to sense the increased oxygen level in the pipe. Thus, the check engine light will stop illuminating.
Closes Open Loops
Hydrocarbons of gasoline also generate an enormous amount of water. This increased amount of oxygen will raise the fuel-to-air ratio, creating an open loop. As a result, this will trigger the check engine light to flash. The spacer will read the lean condition in the exhaust stream and close the open loop.
Read Normal Level Of CO2
Sometimes, this increased gas flow will direct the oxygen sensor to sense an expanded level of carbon dioxide. The Engine Control Unit (ECU) will detect it as a fault and trigger the check engine light. Then the sensor spacer will read the normal level of carbon dioxide and will fix this issue.
Passes Emission Test
Mainly, the downstream sensor monitors the cat output and whether the voltage remains constant. As a result, attaching a sensor spacer downstream will help pass the emission test.
CAT Efficacy Test
Generally, ECU will be sure about a working catalytic converter (cat) when the downstream voltage is flatline somewhere near 450mV. The sensor spacer blocks gases from the cat and from contacting the sensor.
As a result, the downstream voltage will set around 450 mV, indicating the cat’s effectiveness. Thus, it will pass the cat efficacy test.
When you use an oxygen spacer upstream, it will read the oxygen level at a reduced level. To compensate for this, it will lean the air-fuel ratio. This is great for fuel economy.
Tricks The ECU
Sometimes, using an oxygen sensor spacer hampers the instant reading capability of the sensor. Consequently, it takes time for the sensor to sense the changes in the gaseous mixture. Due to this slow change in the output stream reading, the ECU thinks that the cat is operating properly.
Solves The CAT Efficacy Error
There should be a significant difference between the post and pre-cat oxygen sensor readings. Otherwise, you might have to face an efficiency error in the cat.
To fix this issue, the post-cat sensor must read leaner than the pre-cat oxygen sensor. And an oxygen sensor spacer in the post-cat exhaust line solves this issue.
What Are The O2 Sensor Spacer Installation Procedures?
The installation process of the oxygen sensor spacer is relatively straightforward. Thus, you can install the sensor spacer yourself by following a few simple steps.
Throughout this process, you will need
- A jack
- A wrench
- A piler
- A heat gun
- Generating oil
- Oxygen sensor spacers
Here are those steps:
Step 1. Let The Engine Cool Down
You can’t continue with the process if the engine is still hot. If you just drove the car, wait 30 min until it becomes cold. The oxygen sensor is generally attached to the exhaust system, and it will get hot when the engine is running or hot.
Step 2. Lifting The Car
You need to lift them by using a jack. This will create enough room beneath the car so that you can move easily there. Make sure you are jacking it properly and that the jack stand is stable.
Step 3. Locating The Oxygen Sensor
Now, you have to locate the oxygen sensor. Generally, a car can have one to multiple oxygen sensors.
If your vehicle has two oxygen sensors, you will find one near the engine cylinder. Another will be somewhere near the catalytic converter on the exhaust manifold.
Generally, you will have to attach oxygen sensor spacers on the rear oxygen sensor. Thus, crawling down under the car, you will find a spark plug-like part.
A black and thick wire will come outward from that part. Now, you can easily access the oxygen sensor near the Catalytic converter.
Step 4. Disconnecting The Sensor
To disconnect the sensor from the exhaust manifold, you have to unscrew the sensor. Use a wrench and turn it anti-clockwise to disconnect it from the system.
Sometimes, the sensor can be stuck, and it becomes hard to remove it. You can apply any penetrating oil on the sensor to solve this issue.
Then, you will have to wait 5-10 minutes, and the oil will work as a lubricating agent here. You can also use a heat gun to heat its threads and base to make the connection lose.
Step 5. Installing The Sensor Spacer
Now, after removing the sensor, you need to install the sensor spacer on the bank-2 exhaust pipe.
Before installing the spacers, you have to lock up the screw which attaches to the catalytic converter. This way, you will lessen the risk of it falling inside the exhaust.
Put the spacer on the point where the oxygen sensor was. Now, keep spinning it clockwise to tighten the attachment. Afterward, use a wrench to make the attachment firm.
Step 6. Attach The Oxygen Sensor
While removing the sensor, you rotated it anti-clockwise. Thus, while fastening it to the oxygen sensor spacer, you need to rotate it clockwise. After turning it until the last thread, you have to use a wrench to tighten its attachment.
Can O2 Sensor Spacer Cause Problems?
Installing an oxygen sensor spacer on the exhaust pipe may create some disfavors. Here are those:
- If you install the spacer before the cat, it will control the air/fuel ratio of your vehicle. Sometimes, the car could run in a too-lean condition which is risky
- You may also encounter a loss in the torque of the low end
- Installing the spacer will trick the ECU into thinking that the cat is working correctly when it is not. This may cause severe damage to your engine in future
- Although you can solve the check engine light issue by this, it can guarantee the actual problem is solved
- Installing an oxygen spacer is going to create a dead spot in the exhaust pipe. On this spot, exhaust gas won’t come in contact with the sensor
Thus, if, for some unforeseen reasons, the air-fuel ratio changes, the sensor will not sense that. As a result, you will experience unresponsiveness or misfires from your car’s engine
- 90° oxygen sensor spacers are susceptible to producing a p2196 code. This means the front sensor is stuck in the rear condition. This occurs because 90° spacers restrict the exhaust gas from reaching the post-cat oxygen sensor
In this FAQs section, we will answer a few common questions about oxygen sensor spacers.
How Many O2 Sensor Spacers Should I Install?
Though cars might have multiple oxygen sensors, you will need to install only one oxygen sensor spacer. You need to install it on the sensor and after the catalytic, mainly near the rear portion of the car.
Is Installing O2 Sensor Spacers Worthwhile?
Yes. The price of an oxygen sensor adapter may vary between $7-$45, depending on the quality and brand. With this low cost, you can avoid replacing the oxygen sensor. Thus, it’s worthwhile to install an O2 sensor spacer.
What Will Be The O2 Reading After Using A Sensor Spacer?
If you use the oxygen sensor spacers in an upstream flow, the reading in the exhaust will show the reduced concentration of oxygen. But if you eliminate the cat, the reading will show an average level of oxygen.
Oxygen sensor spacers have an excellent role in controlling the ECU. It tricks the ECU into ignoring the increased ppm level of gas in the exhaust stream.
This way, it will prevent or fix the flashing of the check engine light. It also prevents cat efficiency errors.
If you have been here from the start, you already know, “What do O2 sensor spacers do?” Also, it’s a simple task to install an oxygen sensor spacer if you follow the steps accurately that we brought up earlier.
But, there are also several problems that will arise because of using the oxygen sensor spacers.