5 Symptoms of a Bad Oxygen Sensor and Replacement Cost

The oxygen sensor is located inside of the exhaust manifold of a vehicle. Its purpose is to keep track of the level of oxygen which remains unburned in the exhaust system while exhaust is leaving the engine. That way, the fuel mixture of oxygen and gas can be assessed properly because it will tell the computer if there is too much oxygen or not enough. Then, whatever the sensor indicates, the computer will make the proper modifications so that more oxygen or less oxygen will be supplied.

Top 5 of a Bad Symptoms of Oxygen Sensor

The oxygen sensor of the vehicle needs to be in top working order so that the internal combustion of air and fuel can be balanced. If the oxygen sensor were to become damaged or malfunction, the entire internal combustion process of the engine will be in jeopardy. Below are the top 5 symptoms of what you will experience when the oxygen sensor goes bad in your vehicle.

  1. Bad Vehicle Performance – The vehicle will move very poorly. You will notice a lot of stalling as you try to accelerate the vehicle and just an overall sluggishness in the way the vehicle moves. This will become dangerous when you’re out on the road where maintaining a certain speed or performance level is crucial for everyone’s safety and security.
  2. Fails a Smog Test– If you go to get an emissions test on your vehicle and it fails, then it is likely because your car is producing too much carbon emissions or not enough. Either way, there is a 50% chance that this could be caused by faulty oxygen sensors. This is a statistic that was discovered by the Environmental Protection Agency and the California Air Resource Board.
  3. Bad Smell–Do you notice a rotten egg-like smell coming out of your exhaust? This is likely an early warning sign that something is wrong with your oxygen sensor. If left untreated, this rotten egg smell may even spread to the inside of your car which will make it a very unpleasant experience while driving. You’d be better off taking care of it right away.
  4. Engine Light is on – One early warning sign that your vehicle has a bad oxygen sensor is when the engine light on the dashboard turns on. Although this could happen for a variety of reasons, the simplest reason is because of a bad oxygen sensor. Regardless, you should always bring your car to a mechanic as soon as you see the engine light turn on. It could mean any number of problems with your engine and you certainly don’t want to risk letting them go for too long.
  5. Bad Fuel Mileage– When you have a bad oxygen sensor, the mixture of fuel and air will likely be very rich. In other words, a lot more fuel will be consumed in the internal combustion process. This will mean that your miles-per-gallon will decrease because your car will consume more gas just to drive fewer miles. So, if you notice that you have to fill up your gas tank more than usual, that is likely caused by a bad oxygen sensor.

Read also: 5 Symptoms of a Bad Starter Motor and Replacement Cost

Oxygen Sensor Replacement Cost

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To replace an oxygen sensor, the average cost will start at $198 and go up to $276. The price will depend on the make and model of your vehicle as well as the auto body shop in which you bring your vehicle to. These total costs are made up of labor costs, which average from $44 to $56, and parts costs, which average from $154 to $220. There may also be additional fees and sales taxes added onto these prices as well.

2 thoughts on “5 Symptoms of a Bad Oxygen Sensor and Replacement Cost”

    • The sensor could be fouled from a rich air fuel mixture, or there could be a wiring issue. Sometimes cars will throw O2 sensor codes for other issues as well; it may not be a problem with the O2 sensor itself.


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