Moderate SeveritySafe to drive (short-term)Fuel System
P0102 means the mass air flow sensor is reporting a voltage or frequency below the expected idle minimum. The ECU thinks almost no air is entering the engine, so it cuts fuel injection accordingly. The root cause is usually a contaminated MAF element, a major air leak after the sensor, or a wiring fault.
Estimated repair costFrom €8 to €350+, varies by vehicle
What does P0102 mean?
P0102 means the mass air flow sensor is reporting a voltage or frequency below the expected idle minimum. The ECU thinks almost no air is entering the engine, so it cuts fuel injection accordingly. The root cause is usually a contaminated MAF element, a major air leak after the sensor, or a wiring fault.
P0102 is a fuel system-related diagnostic trouble code classified as moderate severity. When your vehicle's ECU detects this condition, it stores P0102 and illuminates the check engine light.
What are the symptoms of P0102?
If your vehicle has triggered P0102, you may notice one or more of these symptoms:
Here are the most common causes of P0102, ranked by how likely they are to be the culprit:
highHeavily contaminated MAF sensor element from dirty air filter or oiled performance filter
highLarge air leak between MAF sensor and throttle body (split intake boot, loose clamp)
mediumDamaged or chafed MAF signal wire shorted to ground
mediumFailed MAF sensor (hot-wire or hot-film element burned out)
lowBlocked or collapsed air intake duct restricting airflow upstream of MAF
Is it safe to drive with P0102?
Generally yes, for short-term driving. Driveable but the engine will run poorly. With abnormally low MAF readings, the ECU under-fuels the engine, causing lean conditions, hesitation, and possible stalling. Safe to drive to a shop, but long-term lean running can damage catalysts and valves.
How do you diagnose P0102?
Follow these steps to pinpoint the root cause of P0102:
Read live data and check MAF reading at idle. A 4-cylinder should show 2–7 g/s. Below 1 g/s is consistent with P0102
Inspect the air filter and replace if dirty (a clogged filter pushes MAF readings low)
Inspect the intake tract from the MAF housing to the throttle body or turbo for cracks, loose clamps, or disconnected hoses
Clean the MAF sensor using a dedicated MAF cleaner spray (never use brake cleaner or carb cleaner)
If readings remain low after cleaning and the intake is sealed, unplug the MAF and test drive. If the car runs better, replace the sensor
How much does P0102 cost to fix?
Repair costs for P0102 vary depending on the root cause and your vehicle. Here are typical estimates:
Repair
Parts Cost
Labor Cost
Total Estimate
DIY Difficulty
Clean MAF sensor with MAF-specific cleaner
€8–€20
€0–€60
€8–€80
Easy
Replace MAF sensor
€40–€250
€30–€80
€70–€330
Easy
Repair intake boot or charge pipe air leak
€20–€150
€60–€200
€80–€350
Moderate
Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.
P0102 on specific vehicles
P0102 behaves differently depending on your vehicle. Select your car below for model-specific causes, known issues, and adjusted cost estimates:
P0102 on BMW 3 Series
BMW 3 Series • 2006–2024
BMW N52, N54, and N55 engines use Bosch hot-film MAF sensors that degrade reliably around 120,000 km. The MAF element becomes coated with crankcase oil mist from the PCV system, which lowers its readings. On the N54, P0102 often accompanies a cracked intake charge pipe under the manifold. INPA shows live MAF values in g/s for comparison against the workshop spec.
What causes P0102 on a BMW 3 Series?
BMW 3 SeriesN52/N54/N55 hot-film MAF degradation at 120,000+ km from PCV oil mist
BMW 3 SeriesN54 cracked charge pipe creating boost leak after MAF
P0102 repair cost for BMW 3 Series
Estimated costs for BMW 3 Series ownersadjusted higher than average due to BMW-specific parts pricing
Repair
Parts Cost
Labor Cost
Total Estimate
DIY Difficulty
Clean MAF sensor with MAF-specific cleaner
€11–€28
€0–€84
€11–€112
Easy
Replace MAF sensor
€56–€350
€42–€112
€98–€462
Easy
Repair intake boot or charge pipe air leak
€28–€210
€84–€280
€112–€490
Moderate
Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.
P0102 on Volkswagen Golf
Volkswagen Golf • 2008–2024
The Golf TFSI (EA888) commonly throws P0102 when the carbon buildup on intake valves restricts airflow enough to skew MAF readings low at idle. Walnut blast cleaning of the intake valves is the standard fix on the EA888. The intake charge pipe between the MAF and throttle body also cracks at the dogbone mount on high-mileage cars, creating air leaks after the sensor.
What causes P0102 on a Volkswagen Golf?
Volkswagen GolfEA888 intake valve carbon buildup restricting airflow past MAF
Volkswagen GolfCharge pipe cracking at dogbone mount on high-mileage TSI
P0102 repair cost for Volkswagen Golf
Estimated costs for Volkswagen Golf ownersadjusted higher than average due to Volkswagen-specific parts pricing
Repair
Parts Cost
Labor Cost
Total Estimate
DIY Difficulty
Clean MAF sensor with MAF-specific cleaner
€9–€23
€0–€69
€9–€92
Easy
Replace MAF sensor
€46–€288
€35–€92
€81–€379
Easy
Repair intake boot or charge pipe air leak
€23–€173
€69–€230
€92–€402
Moderate
Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.
P0102 on Audi A4
Audi A4 • 2008–2024
B8 A4 2.0 TFSI is notorious for MAF failures around 100,000 km. The Bosch hot-film element loses sensitivity from carbon and oil contamination. VCDS shows long-term fuel trims pinned above +20% before the code sets. Always inspect the PCV diaphragm at the same time, since a leaking PCV causes oil contamination that ruins replacement sensors quickly.
What causes P0102 on a Audi A4?
Audi A4B8 2.0 TFSI MAF sensor failure at 100,000 km from oil contamination
Audi A4PCV diaphragm leak destroys replacement sensors quickly
P0102 repair cost for Audi A4
Estimated costs for Audi A4 ownersadjusted higher than average due to Audi-specific parts pricing
Repair
Parts Cost
Labor Cost
Total Estimate
DIY Difficulty
Clean MAF sensor with MAF-specific cleaner
€10–€25
€0–€75
€10–€100
Easy
Replace MAF sensor
€50–€313
€38–€100
€88–€413
Easy
Repair intake boot or charge pipe air leak
€25–€188
€75–€250
€100–€438
Moderate
Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.
P0102 on Ford Focus
Ford Focus • 2011–2024
The Focus 1.6 and 2.0 EcoBoost engines are sensitive to MAF contamination because of high blow-by rates from the turbo. Ford specifically recommends MAF cleaning every 30,000 km on EcoBoost engines as part of preventive maintenance. P0102 on EcoBoost frequently resolves with a single clean. Aftermarket air filters and missed services accelerate the problem.
What causes P0102 on a Ford Focus?
Ford FocusEcoBoost MAF contamination from high blow-by, needs cleaning every 30,000 km
Ford FocusAftermarket oiled air filters accelerate contamination
P0102 repair cost for Ford Focus
Estimated costs for Ford Focus ownersadjusted lower than average due to Ford-specific parts pricing
Repair
Parts Cost
Labor Cost
Total Estimate
DIY Difficulty
Clean MAF sensor with MAF-specific cleaner
€7–€18
€0–€54
€7–€72
Easy
Replace MAF sensor
€36–€225
€27–€72
€63–€297
Easy
Repair intake boot or charge pipe air leak
€18–€135
€54–€180
€72–€315
Moderate
Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.
Related diagnostic codes
These codes are often seen alongside P0102 or indicate related issues:
Yes, short distances. The engine runs lean and rough because the ECU under-fuels based on the low MAF signal. Long-term lean running damages catalytic converters and exhaust valves, so plan the repair within a week.
Will cleaning the MAF fix P0102?
Often yes. Around half of P0102 cases are resolved by a proper clean with MAF-specific cleaner. Never touch the sensing element with anything, and never use brake or carb cleaner since they leave residue that destroys the hot-wire.
Why does my car run worse after cleaning the MAF sensor?
Three common reasons. First, residue from the wrong cleaner contaminated the element. Second, the sensor was already failing and cleaning revealed the underlying fault. Third, the air filter or intake boot was not reseated correctly, creating a new air leak. Inspect all three before replacing the sensor.
How long does an MAF sensor last?
Typically 150,000–250,000 km on petrol engines if the air filter is changed regularly. Diesel MAF sensors tend to last longer (less contamination from PCV blow-by). BMW N52/N54/N55 and Audi 2.0 TFSI MAF sensors are well-known early failures, often before 120,000 km, especially with aftermarket oiled air filters.
