Symptoms of a Bad or Failing Mass Airflow Sensor

Our certified mechanics come to you · 12-month, 12,000-mile warranty

GET A QUOTE Get a fair and transparent estimate upfront
Red-stars EXCELLENT RATING ON

Cost of Replacing a Bad or Failing Mass Airflow Sensor

Common signs of problems with a mass airflow sensor include running rich at idle or lean under load, decrease in fuel efficiency, and rough idles. 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 Mass Airflow 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
2005 Mitsubishi Outlander $223 $153.16 $70.00 14% $260.66
2014 Toyota 4Runner $264 $193.66 $70.00 12% $301.16
2010 Mercury Mountaineer $203 $132.73 $70.00 15% $240.23
2007 Mercedes-Benz E320 $704 $633.60 $70.00 5% $741.10
2008 BMW 128i $369 $299.31 $70.00 9% $406.81
2013 Porsche Cayenne $342 $272.10 $70.00 9% $379.60
GET A QUOTE FOR YOUR CAR Get a fair and transparent estimate upfront

How to Diagnose a Bad or Failing Mass Airflow Sensor?

mass airflow sensor

Mass Airflow Sensors (MAF) have the responsibility of reporting the amount of air entering the engine to the Powertrain Control Module (PCM). The PCM uses this input to calculate engine load.

There are several designs of MAF sensors, but the most common by far is the hot wire MAF sensor. The hot wire MAF has two sensing wires. One wire is heated and the other is not. The microprocessor (computer) inside the MAF determines the amount of air entering the engine by how much current is required to keep the hot wire about 200 ℉ hotter than the cold wire. Whenever the temperature difference between the two sensing wires changes, the MAF will either increase or decrease the current to the heated wire. This equates to more air into the engine or less air into the engine.

There are a number of driveability issues that arise from faulty MAF sensors.

1. Runs rich at idle or lean under load

These symptoms indicate a MAF that has a contaminated hot wire. The contamination can come in the form of spider webs, potting compound from the MAF sensor itself, dirt that gets attached to oil on the MAF from an over-oiled aftermarket air filter, and more. Anything that acts like insulation to the hot wire will cause this type of issue. The fix is as simple as cleaning the MAF sensor with an approved cleaner, which the technicians at YourMechanic can do for you if they determine that this is the root problem.

2. Constantly runs rich or lean

A MAF sensor that continuously over-reports or under-reports airflow into the engine will cause an engine to run rich or lean. If the engine control system is working correctly, you will probably never notice this except for a change in fuel economy. A trained technician will have to look at fuel trim status with the use of a scan tool to verify this. A MAF sensor that behaves like this will require replacement. Before replacing the sensor, however, the rest of the circuit should be checked for proper operation. If the circuit has an issue, replacing the sensor will not solve your problem.

3. Rough idle or stalls

A completely failed MAF sensor will not send any airflow information to the PCM. This prevents the PCM from accurately controlling fuel, which will result in an engine that either will idle roughly or not at all. Obviously, replacing the MAF sensor is needed in this case.

Sensors
MAF (Mass Air Flow) sensors
fuel economy

Fast and easy Mass Airflow Sensor Replacement service at your home or office.

GET A QUOTE FOR YOUR CAR
Get a fair and transparent estimate upfront

Recent Mass Airflow Sensor Replacement reviews

Excellent Rating


YourMechanic Mass Airflow Sensor Replacement Service

Average Rating

4.8/5

Number of Reviews

147

Rating Summary
140
3
0
0
4
140
3
0
0
4

Joel

18 years of experience
562 reviews
Joel
18 years of experience
Very prompt, friendly, courteous and knowledgeable. This is my sons first car and he was clueless. Joel put him at ease. We will definitely ask for him in the future should the need arise.
1990 OLDSMOBILE DELTA 88 - MASS AIRFLOW SENSOR - ATLANTIC BEACH, FLORIDA

Joe

40 years of experience
576 reviews
Joe
40 years of experience
Excellent, very friendly and experienced in all phases automotive maintenance.
1992 FORD RANGER - MASS AIRFLOW SENSOR - TAMPA, FLORIDA

Richard

18 years of experience
169 reviews
Richard
18 years of experience
On time and clearly explained repairs
2008 HYUNDAI TUCSON - MASS AIRFLOW SENSOR - NAPLES, FLORIDA

Milton

34 years of experience
159 reviews
Milton
34 years of experience
Very professional, and informative.
1999 GMC YUKON - MASS AIRFLOW SENSOR - HENDERSON, NEVADA

More related articles

Insurance Requirements for Car Registration in Kentucky
The Kentucky Transportation Cabinet requires that all drivers in Kentucky carry liability automotive insurance, or “financial responsibility” in order to operate a vehicle legally and maintain vehicle...
Veteran and Military Driver Laws and Benefits in New Mexico
The state of New Mexico offers a number of benefits and perks for those Americans who have either served in an Armed Forces branch...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...

Related questions

Q: Station wagon sputters and hesitates

It will depend on the the fault that is stored causing the service engine soon light to be illuminated. Based on the description, I would suspect either an input sensor to the engine management system, such as an oxygen sensor,...

Q: Kia Cerato 2011 jerks when accerating

Your car's engine intake system has something called a mass air flow sensor that monitors air intake as it is mixed with fuel prior to being injected into the motor. When this fails, this can cause an imbalanced air/fuel load...

Q: What Happens if I Overinflate My Tires?

Inflating tires to the correct pressure is one of the most important factors when inflating a tire. Both under and, over-inflating a tire can actually be detrimental to the performance of a vehicle and to the life of a tire....

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1-800-701-6230 · hi@yourmechanic.com