What is the difference between P0100 and P0104?

Both point at the MAF sensor circuit rather than a dirty sensor or an air leak alone. P0100 means the circuit has failed in a way the engine computer sees continuously, while P0104 means the fault comes and goes. That makes P0104 mostly a hunt for a loose connection, a breaking wire or a sensor that fails when hot or shaken.

Can I drive with P0104?

Only gently, and only to a workshop. When the signal drops out the engine can stumble, lose power or drop into limp mode without warning, which is a real risk while overtaking or joining fast traffic. Between episodes the car may feel fine, but the fault will not repair itself.

Why does P0104 keep coming back after I clear it?

Because clearing the code does not touch the cause. An intermittent fault only sets the code again when the conditions return, such as a bump that moves the plug, engine heat that opens a cracked joint, or rain reaching a corroded connector. Look at the freeze frame to see when it happened, then wiggle-test the harness and check the plug before replacing parts.

Can a dirty MAF sensor cause P0104?

It can contribute, but it is not the usual cause. A dirty element tends to read consistently wrong, which is more likely to set P0101. An erratic signal points first at the connector, the wiring or the sensor's electronics, and at air leaks around the sensor. Cleaning is cheap enough to try, but check the connections first.

How much does it cost to fix P0104?

Cleaning and securing the connector can cost nothing if you do it yourself, or up to about €50 at a workshop. A wiring or pin repair typically runs €70 to €240, and tracing an intermittent fault on a road test adds €60 to €130 of diagnosis time. A replacement MAF sensor costs about €70 to €230 fitted for an aftermarket part and €110 to €380 for an original-equipment one.

P0104: Mass or Volume Air Flow Circuit Intermittent

Quick Answer

Safe to drive (short-term)

P0104 means the signal from the mass air flow (MAF) sensor circuit is cutting in and out or jumping erratically instead of changing smoothly with engine speed and load. The engine computer sees the airflow reading behave in a way real airflow cannot. The cause is usually a loose or corroded connection, a wire breaking inside its insulation or a failing sensor, and because the fault comes and goes it often takes a wiggle test or a road test with live data to find.

Severity: Moderate · Fuel System

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What does P0104 mean?

P0104 is a fuel system-related diagnostic trouble code classified as moderate severity. When your vehicle's ECU detects this condition, it stores P0104 and illuminates the check engine light.

Where it is on the car

Air filter box
Mass airflow sensor (MAF)
Throttle body and throttle position sensor
Intake manifold and MAP sensor
Engine (cylinder head)

What are the symptoms of P0104?

If your vehicle has triggered P0104, you may notice one or more of these symptoms:

Check engine light that comes and goes
Sudden stumble, surge or hesitation, then normal running again
Intermittent loss of power or limp mode, mostly on diesels and turbocharged petrol engines
Occasional stalling at idle or when coming to a stop
Symptoms triggered by bumps, engine movement, rain or engine heat
Higher fuel consumption

What causes P0104?

Here are the most common causes of P0104:

Loose, corroded or damaged MAF connector pins, or a broken locking tab letting the plug move
: high
Wire breaking inside its insulation near the connector, where the harness flexes with engine movement
: high
Failing MAF sensor giving an erratic signal
: medium
Air leak before or after the MAF sensor, such as a split intake boot or a loose clamp
: medium
Poor ground or supply shared with other sensors
: low
Engine computer fault, rarely and only after the wiring has been proven good
: low

Is it safe to drive with P0104?

Generally yes, for short-term driving. The airflow signal can drop out without warning, so the engine may stumble, lose power or go into limp mode in the middle of a manoeuvre, especially on diesels and turbocharged petrol engines. Between drop-outs the car often drives normally, which makes it tempting to ignore. Drive gently and directly to a workshop and avoid situations where a sudden loss of power would matter, such as overtaking or joining a motorway.

How do you diagnose P0104?

Follow these steps to pinpoint the root cause of P0104:

Read every stored code and the freeze frame. The engine speed, load and road speed recorded when P0104 set tell you whether it happens at idle, under load or over bumps
Inspect the MAF connector and harness: check the locking tab, look for green corrosion or water in the plug, and feel along the wires near the connector for a kink or a soft spot where a strand may have broken
With the engine idling, watch the live MAF value (the standard OBD2 airflow reading in grams per second) while you wiggle the connector and harness. A reading that spikes to zero or to maximum as you move it confirms a wiring fault. Generic OBD2 readers update only a few times a second, so a very short drop-out may not show; repeat the test several times
Inspect the intake ducting on both sides of the sensor for splits, loose clamps and a badly seated air filter housing
Road test while logging MAF and engine speed. The airflow value should rise and fall smoothly with engine speed and load; sudden steps or drops that do not match what your foot is doing point to the circuit or the sensor
Check the supply and ground at the connector while the engine runs, ideally under load, because a poor connection can pass a static test and still fail when current flows
If the wiring, connections and intake are sound, replace the MAF sensor
Clear the code and drive over several days, including rough roads and a warm engine, because an intermittent fault can take time to show whether it is really fixed

How much does P0104 cost to fix?

Repair costs for P0104 vary depending on the root cause and your vehicle. Here are typical estimates:

Repair	Parts Cost	Labor Cost	Total Estimate	DIY Difficulty
Clean, reseat and secure the MAF sensor connector	€0–€10	€0–€40	€0–€50	Easy
Repair MAF sensor wiring (power feed, ground or signal) or connector pins	€10–€60	€60–€180	€70–€240	Moderate
Replace MAF sensor (aftermarket)	€40–€150	€30–€80	€70–€230	Easy
Replace MAF sensor (OEM)	€80–€300	€30–€80	€110–€380	Easy
Replace split intake boot or loose clamp	€20–€80	€30–€100	€50–€180	Moderate
Extended diagnosis to trace an intermittent fault (road test with live data)	€0–€0	€60–€130	€60–€130	Professional

Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.

Full repair guides

Mass Airflow Sensor (MAF) Cost

P0104 on specific vehicles

P0104 behaves differently depending on your vehicle. Select your car below for model-specific causes and known issues:

P0104 on Volkswagen

Volkswagen Golf

See Volkswagen-specific causes & cost

P0104 on Audi

Audi A4

See Audi-specific causes & cost

These codes are often seen alongside P0104 or indicate related issues:

Common questions about P0104

What does P0104 mean?: P0104 means the engine computer has seen the mass air flow (MAF) sensor signal behave intermittently: dropping out, spiking or jumping in a way real airflow cannot. The sensor and its circuit work some of the time, which is why the car may drive normally for days between episodes.
What is the difference between P0100 and P0104?: Both point at the MAF sensor circuit rather than a dirty sensor or an air leak alone. P0100 means the circuit has failed in a way the engine computer sees continuously, while P0104 means the fault comes and goes. That makes P0104 mostly a hunt for a loose connection, a breaking wire or a sensor that fails when hot or shaken.
Can I drive with P0104?: Only gently, and only to a workshop. When the signal drops out the engine can stumble, lose power or drop into limp mode without warning, which is a real risk while overtaking or joining fast traffic. Between episodes the car may feel fine, but the fault will not repair itself.
Why does P0104 keep coming back after I clear it?: Because clearing the code does not touch the cause. An intermittent fault only sets the code again when the conditions return, such as a bump that moves the plug, engine heat that opens a cracked joint, or rain reaching a corroded connector. Look at the freeze frame to see when it happened, then wiggle-test the harness and check the plug before replacing parts.
Can a dirty MAF sensor cause P0104?: It can contribute, but it is not the usual cause. A dirty element tends to read consistently wrong, which is more likely to set P0101. An erratic signal points first at the connector, the wiring or the sensor's electronics, and at air leaks around the sensor. Cleaning is cheap enough to try, but check the connections first.
How much does it cost to fix P0104?: Cleaning and securing the connector can cost nothing if you do it yourself, or up to about €50 at a workshop. A wiring or pin repair typically runs €70 to €240, and tracing an intermittent fault on a road test adds €60 to €130 of diagnosis time. A replacement MAF sensor costs about €70 to €230 fitted for an aftermarket part and €110 to €380 for an original-equipment one.

Read our detailed guides

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