OBD-II trouble code
P2280: Air Flow Restriction / Air Leak Between Air Filter and MAF
Something is wrong in the short stretch of ducting that runs from the air filter to the mass airflow sensor. Despite the name, the fault here is far more often a blockage than a hole.
Quick facts
- System
- Powertrain
- Category
- Fuel & Air
- Severity
- Low severity
- Drivable
- Usually safe to drive short-term
- Repair cost range
- $0 – $350
- DIY difficulty
- Beginner DIY
Browse every code in P2200–P229F, or start from the full code library.
What does P2280 mean?
This code points at one specific segment of the intake tract: everything from the mouth of the airbox, through the filter element, to the face of the mass airflow sensor. The module concludes that the air arriving at the sensor is not the clean, unobstructed stream the calibration assumes.
The half of the title that gets read first is 'air leak', and that half is the less useful half. A hole in this segment is unusual as a driveability problem, because air entering ahead of the mass airflow sensor still has to travel through the sensor to reach the engine, and the sensor counts it. What an upstream hole really does is let dust bypass the filter element, which is a long-term wear problem for the sensor and the cylinder bores rather than a mixture problem the module can feel this week.
Restriction is the other half of the title and the one that sets this code most of the time. A filter that has never been changed, a snorkel packed with leaves or a rodent nest, a filter fitted upside down so the rubber sealing lip blocks part of the face, a soaked element after a deep puddle, or an inlet duct that has collapsed inward because its internal support ring has broken — all of these choke the flow, and a choked engine reports a peak airflow number lower than its displacement and speed can account for. That mismatch is what the module flags.
There is one more population worth calling out, because it accounts for a great many of these codes on otherwise healthy vehicles. Aftermarket intake kits relocate the mass airflow sensor into a tube of a different diameter and with a different approach length. The sensor is calibrated to the airflow profile of the original tube, not just to the quantity of air, so the same amount of air read through a wider or shorter pipe produces a different signal. On a vehicle carrying this code with a non-standard intake, the first diagnostic move is often to refit the original airbox and see whether the complaint leaves with it.
Common causes
- Air filter element clogged, saturated with water, or long past its service interval
- Rodent nest, leaves or other debris packed into the airbox or the inlet snorkel
- Air filter installed in the wrong orientation, blocking part of the element face
- Inlet duct collapsed or crushed, often after airbox or battery work
- Aftermarket cold-air intake that puts the sensor in a tube the calibration does not match
- Split or disconnected ducting between the airbox outlet and the sensor housing
- Airbox lid not latched down evenly, leaving the filter unsealed around its edge
- Contaminated sensing element, commonly from an over-oiled reusable filter
- Restricted snow shield or ram-air scoop on vehicles that use one
Symptoms
- Check engine light, frequently with no change in how the vehicle drives
- Noticeably less power at the top of the rev range while low-speed driving feels normal
- Fuel economy drifting down over several tanks
- A whooshing or sucking noise from the airbox area under acceleration
- Black smoke on hard acceleration if the restriction is severe
- Long crank or stumbling shortly after driving through standing water
- Codes for the airflow sensor itself, such as P0101, appearing at the same time
Diagnostic steps
- 1.Open the airbox and look before testing anything. A packed snorkel, a nest or a filter fitted backwards is visible in under a minute and accounts for a large share of these codes.
- 2.Pull the filter element and hold it up to a light. A filter that blocks the light across most of its area is finished regardless of how many miles are on it.
- 3.Check that the airbox lid clips are all engaged and that the element is seated evenly in its groove all the way around.
- 4.Compare peak mass airflow at wide-open throttle against what the engine should move. As a rough yardstick a healthy naturally aspirated engine reaches roughly one gram per second for each horsepower it makes; a peak well under that points at restriction.
- 5.Run the engine briefly with the airbox lid removed and the filter out. This segment is the only part of the intake you can delete as a test, and a reading that corrects itself confirms the restriction is inside the box.
- 6.Inspect the ducting between the box and the sensor for a collapsed wall, a crushed section or a split, flexing it by hand with the engine running.
- 7.Look for dust tracks on the clean side of the filter or on the inside of the duct. A fine grey trail means unfiltered air has been getting past the element.
- 8.If a non-standard intake is fitted, refit the original airbox and clear the code before buying any parts.
- 9.Inspect the sensing wires or film through the sensor bore for oil film or fuzz, which changes the reading without any restriction being present at all.
Repair cost
$0 – $350
Very often free: reseating a filter, latching a lid properly or clearing a nest costs nothing but time. An engine air filter is $15 to $60 fitted and is the single most common repair for this code. A replacement inlet duct runs $60 to $200. If the sensing element turns out to be contaminated as well, a mass airflow sensor is $80 to $350 depending on the vehicle. Diagnostic time is rarely needed here because the fault is usually visible.
Estimate your repair
Run the numbers for your vehicle
Open the Repair Cost Estimator with engine air filter replacement preselected. Adjust labor rate and vehicle category to fit your situation.
DIY vs shop
This is a beginner-friendly repair. Common hand tools, a free afternoon, and a willingness to follow a procedure are usually enough. The risk of causing a bigger problem is low if you read up on your specific vehicle first.