A manifold absolute pressure sensor, or MAP sensor for short, is used in fuel injected vehicles to measure the air pressure inside the intake manifold of the engine. The MAP sensor sends this information to the electronic control unit, or ECU, which uses this information to adjust the amount of fuel being added at any point to achieve the most optimal combustion. Symptoms of a bad or failing MAP sensor include excessive fuel use and lack of power in your vehicle. You may also become aware of a bad MAP sensor if you car fails an emissions test.
Part 1 of 1: Disconnect and replace bad MAP sensor
- Replacement MAP sensor
- Socket wrench
Step 1: Locate the installed MAP sensor. Being familiar with the part you are looking for should help you locate the bad sensor on your vehicle.
If you do not know where it is or what it looks like, study the replacement part to help you identify it in the engine bay.
To help narrow down your search, keep in mind that there will be a rubber vacuum hose running to the MAP sensor, as well as an electrical connector with a group of wires coming from the connector.
Step 2: Use pliers to remove the retaining clamps. Any clamps retaining the vacuum line should be disconnected and moved down the length of hose to free the vacuum line from the nipple it is connected to on the MAP sensor.
Step 3: Remove any bolts holding the MAP sensor to the vehicle. Use the socket wrench to remove any bolts securing the sensor to the vehicle.
Set them aside in a safe place.
Step 4: Remove the electrical connector plugged into the sensor. Unplug the electrical connector by squeezing the tab down while firmly pulling the connectors apart.
At this point, the sensor should be free to be removed. Remove it and connect the new sensor to the electrical connector.
Step 5: If the MAP sensor was bolted to the vehicle, replace these bolts. Make sure to tighten the bolts, but do not overtighten them. Small bolts will break easily if over-tightened, especially on older vehicles. An easy method to get consistent results is to use a wrench with a short handle.
Step 6: Replace the vacuum line and any clamps that were removed. Once the vacuum hose is reconnected, the replacement is complete.
If this is not a job you feel comfortable with, have an experienced YourMechanic mobile technician replace the manifold absolute pressure sensor for you at your home or office.