How to Replace a Mass Air Flow Sensor MAF
The mass air flow sensor
or MAF is a vital part to your cars
computer system. This
device is used to measure the amount of air being processed through the
engine at any given second. There
are two styles of mass air flow sensors. The more popular type is designed with
a "hot wire" that when air travels across it the ohms reading changes. The system
computer PCM powertrain control module uses this feedback information and adjusts
the fuel and ignition systems
accordingly. The other style of mass air flow sensor uses a mechanical door that
blocks the air passage when the motor is
not running and then opens when
the motor is running.
The faster the engine is running the more the door opens. This mechanical style
of mass air flow sensor is designed with a rheostat which is connected to the computer.
Never the less, both of these mass air flow sensors can wear out or become contaminated.
In most cases changing a mass air flow sensor is a relatively an easy job and should
only take about twenty minutes. (Note: not all cars are equipped with a mass air
flow sensor, consult a
repair manual if
you are unsure of your cars sensor location).
Before we begin park your car on level ground in park with the emergency brake
set. Please wear safety glasses with gloves and protective clothing.
Supplies and Tools Needed to Complete this Job
1. Replacement Mass Air Flow Sensor
2. Screw Driver Set
3. Socket and Ratchet Set
4. Shop Towels
5. Solvent such as Carburetor Cleaner
Instructions
Step 1 - Release both the primary and secondary
hood latch releases. Raise the car's
hood and support it with a prop rod if needed.
Step 2 - Locate the mass air flow sensor in the intake tube or near the
air filter housing.
Step 3 - Remove the mounting hose clamps or rings holding the air tube to the
sensor, then remove the tube.
Step 4 - Disconnect the electrical connector from the mass air flow sensor
Step 5 - Remove the three or four mounting bolts holding the sensor to the body
plate. (Some Ford mass air flow sensors are located inside
the air filter housing).
Step 6 - Loosen and remove the mounting screws holding the sensor to the case,
if any.
Step 7 - Match up the new mass air flow sensor to the old unit, particularly
the electrical connector.
Step 8 - Install the new mass air flow sensor and reassemble.
Note: When the engine first starts with a new mass air flow sensor it might not
run correctly, allow time for the system to recalibrate, about five minutes of
engine run time.
Best Practices
- Always clean the air intake tube and connection points to ensure proper
installation.
If further assistance is needed, our certified car repair technicians are ready
to answer your car questions. Also, gain manufacturer
specific instructions and information by clicking -
Auto Repair Manual
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