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
2013 GMC Yukon $252 $181.96 $70.00 12% $289.46
2011 Volvo XC90 $648 $578.40 $70.00 5% $685.90
2005 Volvo S60 $216 $146.30 $70.00 14% $253.80
2013 BMW 740i $840 $595.36 $245.00 13% $971.61
2009 Mini Cooper $385 $314.86 $70.00 8% $422.36
2012 Porsche Boxster $502 $431.60 $70.00 6% $539.10
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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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Attila

16 years of experience
99 reviews
Attila
16 years of experience
Excellent knowlegable mechanic. Highly recommended. Need more work done and will use him again. Thank you.
2009 LEXUS RX350 - OXYGEN SENSOR REPLACEMENT (FRONT/UPPER/UPSTREAM) - PISCATAWAY, NEW JERSEY

Robert

17 years of experience
381 reviews
Robert
17 years of experience
Robert was absolutely amazing! He actually showed up and made sure my car was taken care of properly , after the horrible experience with 3 other mechanics that all failed to diagnose my car properly , he gave me Faith in ym ,
2008 NISSAN ALTIMA - OXYGEN SENSOR REPLACEMENT (FRONT/UPPER/UPSTREAM, REAR/LOWER/DOWNSTREAM) - DENVER, COLORADO

Luis

9 years of experience
9 reviews
Luis
9 years of experience
I'm so happy with yourmechanic, it's nice to have such a knowledgeable mechanic come to my house. He is worth more than what the charge is.
2005 DODGE RAM 1500 - OXYGEN SENSOR REPLACEMENT (REAR/LOWER/DOWNSTREAM) - ALBUQUERQUE, NEW MEXICO

Brikk

15 years of experience
233 reviews
Brikk
15 years of experience
Brikk is a great guy and knows what he is doing. Anyone that has the chance to use his experience and knowledge will be lucky like I was. I highly recommend him for any repair job you might have with any of your automobiles. steve t. / Charlotte, NC 28211
2000 CHEVROLET TAHOE - OXYGEN SENSOR REPLACEMENT (FRONT/UPPER/UPSTREAM) - CHARLOTTE, NORTH CAROLINA

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