An oxygen sensor’s primary purpose in a vehicle is to help control emissions and ensure the exhaust system is working normally. Most new car models with four cylinder engines have two oxygen sensors, one in front of the catalytic converter and another one behind. Some vehicles such as V6 and V8 have even more oxygen sensors to help fast-track their many sophisticated systems. The oxygen sensor also plays an important role in ensuring that the environment stays clean every time. Otherwise, this handy guide covers everything about how many oxygen sensors does a car have, how can you tell if an oxygen sensor is bad, how to clean oxygen sensor and more. Let’s get started!
How Do Oxygen Sensors Work?
Oxygen sensors usually generate electricity on the basis of their exhaust system’s specific output. The computer then subsequently detects this variance in voltage before making any changes to the fuel mixture. The voltage levels range from -0.9 to 0.1 volts, which alerts the computer whether the mixture is either too rich or is too lean. Ideally, a high voltage means the exhaust from the engine is rich and, thus, it would be vital to lean the mixture out.
Sometimes the sensor’s voltage output can fail or the variance in voltage can become sluggish, thus causing the computer to work slower than usual. Because of this, the vehicle’s check engine light goes on as a consequence. Tracking which sensor has malfunctioned can sometimes be a difficult and very challenging affair. Many times people have no other option but to use some cutting-edge scanning tools in order to access the car’s computer system.
It’s important to note that other sensors within would also be checking the performance of the catalytic converter. The O2 sensor found in front of the catalytic converter function is to adjust the mixture of the fuel, while the sensor located behind job is to fast-track the catalytic converter’s overall performance and efficiency.
How Can You Tell If an Oxygen Sensor Is Bad?
Oxygen sensors are quite cheap and changing them on a regular basis can help prevent more serious issues from occurring. Their purpose is to check the ratio of gasoline and air in the vehicle’s engine so its computer can make necessary adjustments. The level of oxygen found in engines depend on the surrounding air temperature, altitude, load on the engine, barometric pressure, and the engine’s actual temperature among other factors.
The excess fuel that’s left behind after combustion is known as a rich mixture. A lean mixture doesn’t usually have sufficient fuel and this mixture often hides pollutants with nitrogen oxide inside. Below are some common signs that would otherwise indicate that an oxygen sensor is faulty.
- A sharp decrease in fuel mileage
- Failure to pass an emissions test
- Poor performance, engine stalling, and rough idling
- A glowing check engine light
- Code checker identifying O2 sensor failure
- Issues with an older vehicle
Can I Replace My Oxygen Sensor?
O2 sensors should be changed regularly because of the speed with which they wear and tear. More often than not, this job will be handled by an experienced mechanic. Newer sensors can last many miles and, therefore, frequent changes is not always necessary. However, sometimes the exhaust system may develop signs of rust or become vulnerable to premature failure.
On such occasions, it would be great to check first with an experienced technician to see if there’s anything that can be done to fix the problem. Scanners to determine whether or not a sensor is bad are usually cheap and readily available everywhere. These gadgets are also easy to fit into your vehicle’s data link connector. It’s also important to have a car manual within reach every time in case something happens, and you need further information on how you should address the underlying issue.
Once you’ve determined the real cause behind the problem, a repair manual would also guide you on the essential items you should purchase in order to replace the malfunctioned oxygen sensor. After purchasing all the essential items, the decision on whether you should bring your vehicle to a mechanic or whether you should fix the sensor yourself is all up to you.
Guidelines for Replacing the Oxygen Sensor
How often a person should replace their oxygen sensor is usually determined by the age of their vehicle and the type of sensor they have. Newer vehicles (at least those less than 20 years old) will more likely need to have the sensor changed about every 100,000 miles. On the other hand, cars or trucks from the mid-1990s and even much older vehicles may require replacement anywhere from 50,000-70,000 miles. Make sure to check the manufacturer’s guidelines to know after what specific mileages should you replace your vehicle’s sensor.
O2 sensors are also very easy to diagnose and change. Because of the materials and technology in the sensor’s housing, motorists are advised not to attempt to repair a malfunctioned oxygen sensor. It should be replaced anew every time if the device is at all faulty. Some people will tell you that cleaning the sensor might fix the problem and your vehicle might cover a few more miles, but you’re only trying to run away from the inevitable. More often than not, cleaning the sensor doesn’t usually solve anything. It just causes a small delay and sometimes people end up damaging the inside technology making the situation even worse.
Replacing a defective sensor is much like changing a spark plug. Some motorists manage to change the sensor themselves, but you do need some specialized equipment to successfully tackle this particular issue. It’s important not to get any grease or oil on the sensor. Hiring an experienced mechanic could make a big difference, at least these people are experts in the field and would ensure the sensor is placed correctly every time.
How Much Is an Oxygen Sensor?
There’s no doubt that a person can save a lot of cash if they choose to change the sensor themselves. However, things can get messy and cost the vehicle owner more if further damage is done when fixing the sensor. Thus a mechanic could help turn things around. Most mechanics will first ask you to pay a specific marked price, plus another additional fee of labor before any sensor repair can take place. These charges are all part of a mechanic’s daily income.
Oxygen sensors cost around $100, but at a dealership, prices are usually higher and can range from $125-$150 due to the added markup fee. Also labor charges can range from $85-$135 per hour which means you need to plan ahead. This shouldn’t scare you in any way, as most vehicles take only an hour or less at the dealership before they’re collected by their owners.
The market is flooded with a wide variety of aftermarket oxygen sensors, which means one must be very careful when purchasing these types of sensors. A universal O2 sensor is the cheapest among all sensors around. Unlike most sensors, this specific sensor usually has a factory connector for easy plug in. If you choose to buy a universal sensor, you’ll want to cut off and reuse the original connector from the defective sensor nonetheless. Connectors from the original O2 sensors are preferred because of their direct fit and fast installation, thus making them a great option when replacing sensors every time.
How to Clean Oxygen Sensor
A dirty O2 sensor can cause a vehicle’s check engine light to turn on and can also result in your car consuming more gasoline than usual. Fortunately, anybody can clean their vehicle’s oxygen sensor when it gets dirty by following some simple instructions. Below is a step-to-step guide on how to clean an oxygen sensor.
#1 Elevate the Vehicle With a Car Jack
In order to clean the O2 sensor, you’ll first need to find a way to get underneath your vehicle. Make sure that the vehicle is parked on level ground and that the emergency brake is ready before any car lifting can take place. Also, make sure to protect your hands with a strong pair of work gloves before lifting the vehicle. After you’re all set and ready, put the jack under part of your vehicle’s chassis and car frame, and then start lifting the vehicle gradually.
#2 Identify the O2 Sensors
Some vehicles may have more than one oxygen sensor, depending on the make and model of a car. Check your vehicle’s manual to know where specific these sensors could be located. Most cars have at least two oxygen sensors—one in front of the vehicle’s converter, and another one in the car’s manifold. Vehicles with more than one exhaust manifold usually have an O2 sensor inside each one. If your car is of this type, check to see if you’ll find an oxygen sensor inside each exhaust manifold.
#3 Apply Engine Oil on the Sensors
Because most vehicles’ oxygen sensors are rarely changed, it’s very likely that they’d be firmly stuck in place. To loosen this bond, apply some engine oil on the sensors and allow them to sit for about 10-15 minutes. A lubricant like WD-40 is also another great way to loosen sensors. This lubricant works the heavy bond between the sensors until it becomes loose. As a consequence, the job of removing the sensors becomes easier at last. Make sure to use some protective gear, like a pair of goggles or protective eyeglasses, to ensure the engine oil or WD-40 doesn’t get anywhere near your eyes.
#4 Fill a Bucket With Gasoline
Find a large bucket or industrial container and fill it with gasoline as you wait for the sensors to become loose. Once you’ve removed all the oxygen sensors, clean them by soaking the sensors in gasoline. Allow the sensors to soak overnight to ensure effective cleaning.
#5 Remove the Oxygen Sensors from the Housing
After all the oxygen sensors become loose and fully lubricated, grab a wrench and start unscrewing the sensors. As you detach the sensors, make sure not to drop the sensors on the ground or allow them to get dirty. Find a clean plastic bowl and place the sensors there. You can even place them on a flat area so long as it’s clean.
#6 Submerge the Sensors in a Container of Gasoline
Next, immerse the sensors in a bucket or industrial container you’ve just filled with gasoline. Make sure all the sensors are fully submerged in gasoline. Also, ensure that no gasoline splashes out of the container or gets anywhere near your hands. Because this liquid is also highly flammable, never lit a cigarette or candle when working near gasoline to protect yourself from potential harm.
#7 Cover the Bucket With a Lid
Gasoline is a highly flammable substance, so it’s critical to ensure the bucket or industrial container of gasoline is tightly covered at all times. This will ensure the gas doesn’t catch any fire and also prevent any wandering animals from playing about with the gas.
#8 Leave the Sensors to Soak Overnight
O2 sensors take some time before they’re finally clean. It would be great to allow them to soak in the container of gas for at least 8 hours. For even more effective cleaning, raise the container and spin it around for a few seconds.
#9 Pull Out and Dry the Sensors
After you’re through with all the spinning, stretch your hands into the bucket or container of gasoline and pull out all the sensors. The sensors’ appearance should be much cleaner than when you last submerged them into the gasoline. As usual, find a clean cotton cloth and wipe the oxygen sensors until they are fully dry.
#10 Place Back the Oxygen Sensors
Once you’ve wiped the sensors dry, find a wrench and place them back in the exhaust manifolds. Make sure that all sensors are placed back in their former positions from which you last detached them. After you’ve identified all the sensors’ initial locations, fully tighten them back in place.
The oxygen sensor is an important part of a car engine. Its sole purpose is to lower automobile emissions as well as keep the environment clean at all times. Its size is much like that of a spark plug and usually monitors the oxygen levels in a vehicle’s exhaust stream. Hopefully, this handy guide has acquainted every motorist with everything about oxygen sensors, particularly on matters surrounding how many oxygen sensors does a car have, how to clean oxygen sensor, and how you can tell if an oxygen sensor is bad.