P0102 – Mass or Volume Air Flow Circuit low Input

What does P0102 mean?

The mass air flow (MAF) sensor is reporting an airflow signal lower than the expected range. The MAF sensor measures how much air enters the engine so the computer can deliver the matching amount of fuel. A low reading means the computer is not getting accurate airflow data.

What causes P0102?

Listed from most to least common:

1. 1Dirty MAF sensor element (very common — dust and oil film from over-oiled air filters)
2. 2Clogged or dirty air filter restricting airflow
3. 3Air intake leak between the MAF sensor and the throttle body
4. 4Failed MAF sensor
5. 5Damaged wiring or poor connection at the MAF connector
6. 6Collapsed or damaged intake duct

Code breakdown

Common symptoms

• Check engine light on
• Rough idle or stalling
• Hesitation and lack of power on acceleration
• Hard starting
• Poor fuel economy

How to diagnose

1. 1Inspect the air filter and replace it if dirty.
2. 2Clean the MAF sensor element using MAF-specific cleaner only — never touch the wire or use other solvents.
3. 3Inspect the intake duct between the MAF and throttle body for cracks or loose clamps, which let unmetered air in.
4. 4Check the MAF connector and wiring for corrosion, damage, or a loose fit.
5. 5Compare live MAF readings against the expected value for your engine at idle and at higher RPM.

Incorrect airflow data leads to a wrong fuel mixture, which can cause poor running and, if left unaddressed, converter damage.

Common fixes and estimated costs

Costs are rough US estimates including parts and labor. Actual pricing varies significantly by vehicle, region, and shop rates.

Good to know

Over-oiled aftermarket performance air filters are a frequent cause — excess oil coats the MAF element and skews readings. Cleaning the sensor often resolves the code for a few dollars.

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