Symptoms of a Bad or Failing Air Fuel Ratio Sensor

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Cost of Replacing a Bad or Failing Air Fuel Ratio Sensor

If you notice a decrease in fuel efficiency or engine power output, as well as a rough idle, you may have to replace any air-fuel ratio sensors. Our certified technicians can come to you and diagnose the problem. You will receive a $30 credit towards any follow-up repairs that result from the diagnostic. Following are example prices for Oxygen Sensor Replacement. Click on the button below to get an upfront quote for your car.

Cars Estimate Parts Cost Labor Cost Savings Average Dealer Price
2007 Buick Allure $287 $216.96 $70.00 11% $324.46
2013 Chrysler 300 $261 $191.38 $70.00 12% $298.88
2012 Ford Edge $228 $158.04 $70.00 14% $265.54
2013 BMW 328i $620 $451.54 $168.00 12% $709.54
2004 BMW 530i $661 $416.30 $245.00 16% $792.55
2011 Porsche 911 $410 $319.12 $91.00 10% $458.87
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How to Diagnose a Bad or Failing Air Fuel Ratio Sensor?

failing air fuel ratio sensor

An air-fuel ratio sensor is one of the key components found on many modern engine management systems. Most vehicles will have more than one air-fuel ratio sensor. They are mounted in the exhaust system before and after the catalytic converter. The air-fuel ratio sensors continuously monitor the air-fuel ratio of the vehicle’s exhaust and send a precise signal to the engine computer so that it can make real time adjustments to fuel and timing for maximum efficiency and power.

As the air-fuel ratio sensors plays a direct role in the adjustment and tuning of the engine, they are very important to the overall operation and efficiency of the engine and should be inspected if problems arise. Usually, when they begin to have problems, the vehicle will display a few symptoms that can alert the driver that an air-fuel ratio sensor may require attention.

1. Decrease in fuel efficiency

One of the first symptoms of a problem with an air-fuel ratio sensor is a decrease in fuel efficiency. The air-fuel ratio sensor monitors the oxygen content in the exhaust stream and sends data to the computer so that it can add or subtract fuel. If there is any problem with the sensor, it can send a bad or false signal to the computer which can throw off its calculations and cause it to waste fuel excessively. Miles per gallon (MPG) will usually drop over a period of time, until it remains consistently lower than before.

2. Drop in engine power output

Another symptom of a possible problem with an air-fuel ratio sensor is a decrease in engine performance and power output. If an air-fuel ratio sensor has become “lazy,” over time it will send a delayed signal to the computer, which will result in an overall delayed response for the entire engine. The vehicle may experience a sluggish or delayed response when accelerating, as well as a noticeable loss in power and acceleration speed.

3. Rough idle

Another symptom of a bad air-fuel ratio sensor is a rough idle. Because air-fuel mixtures at low engine speeds must be very finely tuned, the air-fuel ratio sensor signal is very important to the idle quality of the engine. A bad or failing oxygen sensor can send an incorrect signal to the computer which can throw off the idle, causing it to drop below the correct level or fluctuate. In severe cases, the idle quality may be impacted to the point where the vehicle may even experience stalling.

Because the air-fuel ratio plays such a vital role in the engine computer’s calculations, it is very important to the overall performance of the vehicle. If you suspect that you may be having a problem with one or more of your air-fuel ratio sensors, have a professional technician, such as one from YourMechanic, diagnose the vehicle and replace any air fuel-ratio sensors if necessary.

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Torrieanto

9 years of experience
303 reviews
Torrieanto
9 years of experience
Great
2003 TOYOTA AVALON - OXYGEN SENSOR REPLACEMENT (FRONT/UPPER/UPSTREAM) - LAKELAND, FLORIDA

Jose

14 years of experience
433 reviews
Jose
14 years of experience
Nice guy. Helped me out with a small issue I had that wasn't part of the appointment.
2003 HONDA ACCORD - OXYGEN SENSOR REPLACEMENT (FRONT/UPPER/UPSTREAM) - PORTLAND, OREGON

Chris

19 years of experience
1240 reviews
Chris
19 years of experience
A++++ Chris arrived ahead of schedule Sunday morning at 7AM and installed two upstream Bosch oxygen sensors that I had purchased online. He is polite, professional and extremely knowledgeable particularly about Mercedes. I saved at least $500 buying my own parts and using this service. Highly recommended !!!
2004 CHRYSLER CROSSFIRE - OXYGEN SENSOR REPLACEMENT (FRONT/UPPER/UPSTREAM) - LAGUNA WOODS, CALIFORNIA

Michael

13 years of experience
379 reviews
Michael
13 years of experience
Helped a lot. Fixed 8 of 10 problems with my car
2000 MERCURY GRAND MARQUIS - OXYGEN SENSOR REPLACEMENT (FRONT/UPPER/UPSTREAM, REAR/LOWER/DOWNSTREAM) - ATLANTA, GEORGIA

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