Asked by: Kin Hueso
automotive auto parts

What is an AF sensor?

Last Updated: 22nd January, 2020

The air fuel ratio sensor is installed in the exhaust manifold or in the front exhaust pipe, before the catalytic converter. The job of the air fuel ratio sensor is to measure the oxygen content in the exhaust and provide feedback to the engine computer (PCM).

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Also, is an A F sensor the same as a o2 sensor?

An air/fuel sensor can read a much wider and leaner range of fuel mixtures than a conventional O2 sensor. That's why they're also called “wideband” O2 sensors. An A/F sensor, by comparison, produces a changing current signal that varies in direct proportion to the amount of unburned oxygen in the exhaust.

Furthermore, can you clean an air fuel sensor? A dirty oxygen sensor can cause your “check engine” light to come on, and can also result in your car burning through extra gasoline. If you suspect that your oxygen sensor may be dirty, you can clean it by first removing the sensor from its housing in the vehicle, and then soaking the sensor in gasoline overnight.

Also know, what are the symptoms of a bad oxygen sensor?

Symptoms of a Bad or Failing Oxygen Sensor

  • Check Engine Light comes on. The first line of defense is the Check Engine Light.
  • Bad gas mileage. If the oxygen sensor is going bad, the fuel-delivery and fuel-combustion systems will be thrown off.
  • Rough engine idle and misfires.

Can I use a downstream oxygen sensor for upstream?

A downstream oxygen sensor in or behind the catalytic converter works exactly the same as an upstream O2 sensor in the exhaust manifold. On some newer vehicles, a new type of wide ratio air fuel sensor is used.

Related Question Answers

Yonaida Balaguero


How do AFR sensors work?

The job of the air fuel ratio sensor is to measure the oxygen content in the exhaust and provide feedback to the engine computer (PCM). Based on air fuel ratio sensor signal, the computer adjusts the air to fuel ratio to keep it at the optimum level, which is about 14.7:1.

Salca Tschirschwitz


How much does it cost to replace a fuel sensor?

The cost of replacing a fuel pressure sensor depends on the make and model of your vehicle. However, on average, you can expect to pay anywhere from $260 to $320 for a replacement job like this. The part itself will only cost you around $65 to $75, but the labor will cost you anywhere from $190 to $250.

Tulia Bernacki


How does a wide band oxygen sensor work?

A wideband O2 sensor or A/F sensor is essentially a smarter oxygen sensor with some additional internal circuitry that allows it to precisely determine the exact air/fuel ratio of the engine. Like an ordinary oxygen sensor, it reacts to changing oxygen levels in the exhaust.

Shasha Schepkin


Can you drive with a bad o2 sensor?

O2 is the oxygen sensor in your vehicles exhaust system to reduce the harmful and poisonous fumes when the motor is running. You can drive it just fine with the broken sensor; it just means the vehicle can't properly monitor and adjust the fuel/air mixture properly. Sometimes its not the sensor at all that failed.

Fredric Larrazabal


Should I replace all o2 sensors at once?

Do I need to replace all of my oxygen sensors at once? It is best to replace your sensors in pairs. For example, if you replace the downstream left sensor, you should also replace the downstream right. It is probable that on most vehicles, the code will be set within 30-60 days AFTER the first sensor replacement.

Uxue Renee


What is Bank 1 and Bank 2 on a car?

Bank 1 and bank 2 simply refer to either side of the engine. Most commonly, bank 1 houses the front most cylinder on the engine cylinder 1, and bank 2 is the opposite side of the engine.

Aleth Helley


How do I know if I have a bad o2 sensor or catalytic converter?

Signs that you may need a new catalytic converter include:
  1. Your car throws a check engine light.
  2. Your engine misfires.
  3. Your car noticeably uses more fuel.
  4. Your car isn't performing the way it used to.
  5. Your car fails an emissions test or it has more emissions than normal.

Jerrica Schliesser


How long does it take to replace an o2 sensor?

The upstream sensor would take about 1.2 hours to replace and the total for parts and labor is $206.08. If it was the downstream sensor the price would be $203.08 and would also take about one 1.2 hours to replace. Please consider replacing your sensor through YourMechanic.

Lelah Vispo


Which 02 sensor is bank 1 sensor 2?

Bank 1 Sensor 2 = This O2 sensor is located right after the catalytic converter, on the side with the Cylinder #1 that is Bank 1. Bank 2 Sensor 1 = This O2 sensor is located right before the catalytic converter, on the side with the Cylinder #2 that is Bank 2.

Guofu Yudochkin


What causes an oxygen sensor to fail?

O2 sensor failures can be caused by various contaminants that enter the exhaust. These include silicates from internal engine coolant leaks (due to a leaky head gasket or a crack in a cylinder wall or combustion chamber) and phosphorus from excessive oil consumption (due to worn rings or valve guides).

Nadiia Mandava


What happens if I don't replace my catalytic converter?

If the CC is damaged, it can impact vehicle performance; mainly cause reduced engine power and fuel efficiency; but in general won't damage the engine significantly. If you're car is due for emissions or registration however, it will most likely not pass.

Yone Zarzana


Can I clean an 02 sensor?

There are no true oxygen sensor cleaners that are safe to put through your engine. While some people choose to remove them and use a wire brush or an aerosol cleaner to remove deposits, we do not recommend trying to clean O2 sensors.

Terencia Llano


Will a oxygen sensor stop a car from running?

Well, the short answer is no, that will not cause the car not to start. If your vehicle is not starting, then you have a more significant issue than the oxygen sensor is dangerous or dirty. The oxygen sensor helps the car run smoothly, but it does not keep the car from not starting.

Artemisa Sunny


What will your car do if o2 sensor is bad?

Symptoms of a Bad Oxygen Sensor
When you have a bad oxygen sensor, your vehicle will run less efficiently, it can sometimes have a poor idle, erratic jerking at steady throttle, hard starting problems, cause the check engine light to come on, and will cause high fuel consumption.

Tawfik Jigmytov


What size socket is an oxygen sensor?

7/8" (22mm). Many times the O2 sensor will be bound pretty tightly, an open end wrench will most likely round off the hex. Get an O2 sensor socket, or you can get a regular deep 7/8" socket, cut the wires to the old O2 sensor, and take it off with the regular socket.

Modesta Madrigal


Can a bad o2 sensor cause a car to jerk?

A defective O2 sensor will likely cause your air-fuel mixture to be too rich and directly affect your fuel economy. Flashing check engine light or malfunction indicator lamp in the vehicle? s dash board. Overall poor vehicle performance; rough idling, stalling, hesitation on acceleration, etc.

Felecia Dawes


How long should an 02 sensor last?

Generally speaking, your oxygen sensor should last somewhere between 50,000 and 60,000 miles. However, if your engine is properly maintained, the sensor(s) may last much longer, up to the life of the vehicle.

Anita Schonduwe


How much does it cost to replace an o2 sensor?

A brand new replacement oxygen sensor can cost you from $20 to $100, depending on the make and year of your car. Taking your car to a mechanic to fix the issue can cost up to $200. Though, this depends on the type of car and the rates of the mechanic.

Guihua Radio


How long does it take for the check engine light to go off after replacing the o2 sensor?

Turn the ignition to the "On" position but don't crank the engine (it won't start anyway). Wait five minutes and reinsert the fuse. The "Check Engine" light will blink, then shut off. This will indicate that your ECU has been reset.