How to Locate, Remove & Clean a Dirty MAP Sensor

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Easy steps to clean your sensor & improve your car’s performance

Co-authored by Devin McSween

Last Updated: April 25, 2024 Fact Checked

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Removing the MAP Sensor

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Cleaning the MAP Sensor

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Things You'll Need

If your car gets lower fuel efficiency, idles roughly, stalls when you accelerate, or has a check engine light that won’t turn off, a dirty manifold absolute pressure (MAP) sensor might be the culprit. This sensor sends data to your engine's electronic control unit to determine the amount of air and fuel needed for combustion. In this article, we’ll show you how to find, remove, and clean your MAP sensor to get your car back to peak performance.

Things You Should Know

Turn off your car and disconnect the battery. Look for the MAP sensor on the intake manifold by the engine, then unscrew and unplug it to remove it from your car.
Spray the long, cylindrical sensor part with mass air flow (MAF) sensor cleaner. Then, wipe the outside of the MAP sensor with the cleaner.
Let the MAP sensor dry completely for at least 5 minutes before reinstalling it.

Part 1

Part 1 of 2:

Removing the MAP Sensor

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1
Park your car, turn it off, and let the engine cool. The manifold absolute pressure (MAP) sensor is connected to your car’s electrical system, so it needs to be off when you remove the sensor. Just find a flat surface to park your car on, like your driveway, and turn it off. Then, allow the engine to cool down for about 10 minutes.
- Do not park on an incline. This reduces the risk of your car moving as you’re working on it.
- Open your car’s hood and lightly touch the engine after 10 minutes. If it's still warm, wait another 5 minutes for it to cool.
Put on gloves and safety glasses. As you remove and clean your car’s MAP sensor, you might be exposed to dirt, oil, debris, and chemicals. So, protect your hands and eyes by wearing gloves and a pair of safety glasses.

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3
Disconnect your car’s battery as a safety precaution. Locate your car’s battery under the hood and look for the negative terminal on top of it. Typically, it is covered with a black cap or labeled with a "-" on top of the connector. Then, use a socket wrench to loosen the nut on the negative terminal by turning the wrench counterclockwise. Disconnect the negative connector and move it away from the battery.
- Repeat the same procedure with the positive terminal and connector. The positive terminal is typically covered in a red cap or marked with a "+" sign.
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Locate the MAP sensor on or near the intake manifold. In most cars, the small, black MAP sensor is mounted directly onto the intake manifold, which is located on top of or to the right of the engine. The MAP sensor is typically behind the silver throttle body and attached to an electrical connector that is fastened to a group of wires. There is usually a rubber vacuum hose that runs to the sensor, too.^{[1]
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- On some cars, the MAP sensor is obscured by the vacuum hose.
- Lift the engine's wiring harness to give yourself a better view of the sensor. Or, loosen the harness by pulling out the plastic ends attached to its wires.
- If you’re not sure where your sensor is located, check your owner’s manual. Or, search for your car’s MAP sensor placement online.
- Some cars have either a MAP sensor or a mass air flow (MAF) sensor. If your car doesn’t have a MAP sensor, clean the MAF sensor to improve your car’s performance.
If your car’s MAP sensor is covered by the vacuum tube, simply unhook the vacuum line with needle nose or retaining ring pliers. Just place your pliers into the 2 holes on the ring surrounding the vacuum tube. Then, squeeze the pliers together to expand the ring and take it off of the vacuum. Remove any other rings from the tube until you can fully unhook the vacuum line from the MAP sensor.
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Unscrew the bolts or screws mounting the sensor to your vehicle. Depending on your car, your MAP sensor might be connected to the intake manifold with 1 to 2 bolts or screws. Simply use a socket wrench or screwdriver to turn them counterclockwise and remove them from the vehicle.^{[2]
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- Keep the bolts or screws in a small container so they don't get lost.
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Unhook the electrical connector and lift out the MAP sensor. Find the black electrical connector that’s hooked into the MAP sensor. Just press down on the clip that’s plugged into the sensor and pull back on the connector to remove it. Then, lift up the sensor while gently wiggling it back and forth to remove it from your car.^{[3]
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- If there is no clip, detach the electrical connector by pressing on the locking tab and pulling it from the MAP sensor.

Part 2

Part 2 of 2:

Cleaning the MAP Sensor

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1
Spray the sensor with mass air flow sensor cleaner. Hold the MAP sensor with the cylindrical sensor facing down; this is the long, protruding part that contains 2 metallic probes. Then, aim the nozzle of the mass air flow (MAF) sensor cleaner at the sensor and give it 2 to 3 spritzes. Just rotate and spray the sensor until the entire sensor is free of buildup and debris.^{[4]
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- Do not touch the sensor directly. The sensor is made up of delicate parts that can be easily damaged.
- Stay away from carburetor cleaner, as it is considered too tough on the sensor.
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Wipe the outside of the MAP sensor with more cleaner and a rag. Place the MAP sensor on a flat surface with the sensor facing upward. Then, spray a clean, dry rag with MAF sensor cleaner and gently rub the exterior of the sensor.^{[5]
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- Carefully wipe the MAP sensor so you don’t accidentally rub the delicate sensor.
To remove any extra MAF cleaner inside the sensor, gently shake and wiggle it. Then, leave the MAP sensor in the sun to dry for about 5 minutes or until it's completely dry.^{[6]
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Use MAF sensor spray to clean the opening to the intake manifold. The hole connecting the MAF sensor to the intake manifold can also get clogged and lead to stalling, idling, and fuel efficiency issues. So, wet a cotton swab with MAF sensor cleaner and insert it inside the hole. Then, rotate it inside the opening to loosen and lift out any buildup and debris.^{[7]
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- Let the opening dry for at least 5 minutes before reinstalling the MAP sensor.
- Check the electrical connector for any debris or corrosion, too. If you see any, spray it with electrical contact cleaner.
5
Reinstall the MAP sensor in your car and hook up the battery. When the MAP sensor is completely dry, secure it back onto the intake manifold with the bolts or screws you removed. Then, plug the electrical connector into the sensor.^{[8]
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Research source} To reconnect the battery, screw the positive connector and then the negative connector back into their respective terminals.
- If you had to remove the vacuum tube around the MAP sensor, snap the retaining rings back on the vacuum line by opening them with your pliers and placing them around the vacuum.
- If you were dealing with your car stalling, low fuel efficiency, a rough idle, or a lit check engine light, cleaning the MAP sensor often solves the issues.
- If you are still experiencing problems, your MAP sensor might just be old or faulty. To replace it, check your car’s manual for a compatible sensor, or search for it online. Then, take out the sensor and pop in a new one.