Toyota 4Runner Mass Airflow Sensor Replacement Cost

Know what price you should pay to get your vehicle fixed.

Mass Airflow Sensor Replacement
The average cost for a Toyota 4Runner mass airflow sensor replacement is between $327 and $865. Labor costs are estimated between $77 and $98 while parts are priced between $250 and $767. Estimate does not include taxes and fees.
Note about price: The cost of this service or repair can vary by location, your vehicle's make and model, and even your engine type. Related repairs may also be needed. Talk with a RepairPal Certified shop to learn which repairs might be right for you.

How does the mass airflow sensor work?

The engine's computer has to receive input from many sensors, and ensure they are in agreement. An extremely important sensor that is used in reference to nearly all engine operations is the mass airflow (MAF) sensor. The MAF sensor records the volume of air that enters the engine's intake tube, and reports that information to the computer. This allows the computer to calculate, or confirm, the amount of air moving into the engine, amount of exhaust gas to expect, the amount of fuel to send into the engine, and many other important factors. Lastly, this sensor works very closely with the manifold absolute pressure (MAP) sensor to allow extremely accurate response to changing conditions.

What are the symptoms related to a bad mass airflow sensor?

If the MAF sensor sends an erroneous signal, a few things happen. The engine's computer will trigger the check engine light, and the on-board diagnostic (OBD) trouble codes will reflect the airflow discrepancy noted by the MAF sensor. Depending on the reported volume of air, the engine may try to compensate for these conditions, causing the engine to burn excessive amounts of fuel and emit black smoke from the exhaust. In this case, the OBD trouble codes would also reference faults recognized by the exhaust oxygen sensors. The engine may also have issues with idling roughly, failing to start, stalling, hesitation, power loss, misfires, and fuel consumption.

»MORE: Signs of a failing mass airflow sensor

Can I drive with a mass airflow sensor problem?

When the MAF sensor fails driving can be dangerous. As engine power will surge on and off, the vehicle may lurch forward. Overall engine performance may become unpredictable and difficult to control. It is preferred to tow the vehicle if any of the mentioned symptoms are present. If the vehicle operates normally, or near normally, driving the vehicle should not cause any issues.

How often do mass airflow sensors need to be replaced?

MAF sensors do tend to fail sometime in most vehicles. Failure rates are highest between 100,000 and 125,000 miles. The sensor can also be damaged during air filter changes, and anytime the engine intake is serviced. Lastly, a collision may cause a physical or electrical fault in the MAF sensor.