P2279: Intake Air System Leak
The ECU has detected a discrepancy between commanded throttle/intake conditions and the resulting MAP/MAF that points to unmetered air entering after the throttle body. On turbocharged engines this often means a cracked or disconnected boost pipe between turbo and intake; on naturally aspirated engines, a hole in the intake manifold or hose.
What P2279 means
P2279 is a generic OBD-II powertrain code in the fuel & air group. In plain English: a self-test found a leak in the system.
- Check engine light
- Usually on
- Emissions-related
- Yes — can fail inspection
- Limp mode possible
- Not typical
- Drive cycle to clear
- Required
Get it fixed
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Common causes
- 01Boost pipe disconnected or crackedMost likely
- 02Intake hose splitMost likely
Can I drive with P2279?
Usually yes, for a short time.
The car will often drive normally, but get it diagnosed soon. Left alone it can raise fuel use and emissions and will fail an OBD inspection. If you notice rough running, warning lights flashing, overheating or a burning smell, stop driving.
Why we rate it moderate
- Turns on the check engine light
- Emissions-related: will usually fail an OBD inspection
- Needs a drive cycle to confirm a repair
Severity is our rule-based rating from the code’s flags in OBDex and the system it affects, not an inspection of your car. If the check engine light is flashing, or you notice overheating, low oil pressure, or brake or steering problems, stop driving and get help.
How to diagnose P2279
- 1
Confirm the code and save freeze-frame data
Read the codes with an OBD-II scan tool and note every code, not just P2279. Save the freeze-frame data (speed, load, temperature when the fault set) before clearing anything; it tells you when the fault happens.
- 2
Fix other faults first
If other codes are stored, start with power-supply, sensor-circuit and communication codes. They can cause this code as a side effect.
- 3
Check live data
Watch the related sensor and actuator readings in live data (Intake manifold, Intercooler pipe, Throttle body) and compare them with expected values in the service information for your vehicle.
- 4
Test the likely causes in order
Start with the most likely cause and work down: Boost pipe disconnected or cracked; intake hose split. Test before replacing parts.
- 5
Check for recalls and service bulletins
Look up recalls for your exact vehicle with its VIN, and ask a dealer about technical service bulletins (TSBs). Manufacturers sometimes issue software updates or extended warranties for known faults.
- 6
Clear the code and verify the repair
After the repair, clear the code and complete a full drive cycle (cold start, idle, steady highway cruise, deceleration). The code is fixed when the related readiness monitor completes without it returning.
P2279 repair cost estimate
Estimate, not a quote. Labor times are typical ranges for this code from OBDex, and $125/hr is an assumed rate. Shop rates and labor times vary by vehicle and region. Diagnosis time may be billed separately.
- DIY difficulty
- Easy
- Good DIY job?
- Yes, with a scan tool
Basic hand tools; a common first DIY job.
Parts and systems involved
- Intake manifold
- Intercooler pipe
- Throttle body
P2279 FAQ
What does P2279 mean?
P2279 means “Intake Air System Leak”. The ECU has detected a discrepancy between commanded throttle/intake conditions and the resulting MAP/MAF that points to unmetered air entering after the throttle body. On turbocharged engines this often means a cracked or disconnected boost pipe between turbo and intake; on naturally aspirated engines, a hole in the intake manifold or hose.
Is P2279 serious? Can I keep driving?
We rate P2279 as moderate severity. Usually yes, for a short time. The car will often drive normally, but get it diagnosed soon. Left alone it can raise fuel use and emissions and will fail an OBD inspection. If you notice rough running, warning lights flashing, overheating or a burning smell, stop driving.
What causes P2279?
The most common causes, from most to least likely: Boost pipe disconnected or cracked; Intake hose split. Test before replacing parts, because several causes can set the same code.
How much does it cost to fix P2279?
Typical labor is about $40–$315 at an assumed $125/hour shop rate, plus parts. That is an estimate, not a quote: labor times and rates vary by vehicle and region, and diagnosis may be billed separately.
Can I fix P2279 myself?
DIY difficulty is easy. Many owners can handle it with a scan tool, a multimeter and basic hand tools. Always confirm the cause before buying parts.
Will P2279 clear itself?
Once the fault is fixed, the check engine light usually goes off by itself after the system passes its self-test over several drive cycles. Clearing the code with a scan tool resets readiness monitors, so an inspection station may turn you away until a full drive cycle is completed.