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DTC/P2279

P2279: Intake Air System Leak

Quick Answer
Moderata GravitàSicuro da guidare (a breve termine)Emissioni

P2279 means the ECU sees more air in the cylinders than the MAF measured, so unmetered air is entering downstream of the sensor and pushing fuel trims positive.

Costo di riparazione stimatoDa €50 a €750+, varia in base al veicolo

Scansiona la tua auto in circa 60 secondi: scopri se P2279 è davvero presente, quanto è urgente e quanto dovrebbe costare la riparazione.

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Cosa significa P2279?

P2279 means the ECU sees more air in the cylinders than the MAF measured, so unmetered air is entering downstream of the sensor and pushing fuel trims positive.

P2279 è un codice diagnostico di guasto relativo a emissioni, classificato con gravità moderate. Quando la centralina (ECU) del tuo veicolo rileva questa condizione, memorizza P2279 e accende la spia motore.

Quali sono i sintomi di P2279?

Se il tuo veicolo ha attivato P2279, potresti notare uno o più di questi sintomi:

  • Rough or unstable idle, sometimes stalling when coming to a stop
  • Hissing or whistling from the intake area, loudest at idle
  • Long-term fuel trims above +10% at idle, dropping closer to zero at 2500 rpm
  • Fuel economy down 5 to 15% over a tank
  • Hesitation or stumble on light tip-in from a stop
  • Companion lean codes P0171 and/or P0174 stored with P2279

Cosa causa P2279?

Ecco le cause più comuni di P2279:

altaCracked or split intake boot between MAF and throttle body
altaFailed PCV valve, torn PCV diaphragm, or split PCV hose
mediaLeaking intake manifold gasket, common on aged plastic manifolds
mediaCracked vacuum line or perished brake booster hose
bassaLeaking throttle body gasket after a cleaning or reinstall
bassaMissing, cross-threaded, or torn-gasket oil filler cap

È sicuro guidare con P2279?

In genere sì, per brevi tragitti. You can drive short distances, but rough idle and lean running can overheat the catalytic converter and trigger misfires. Fix it within a week or two.

Come si diagnostica P2279?

Segui questi passaggi per individuare la causa principale di P2279:

  1. Scan for all stored codes. P2279 usually shows up with P0171 and/or P0174, which confirm the lean condition.
  2. Read live fuel trims at idle and at 2500 rpm. Strongly positive STFT at idle that normalizes at higher rpm points to a small vacuum leak.
  3. Visually inspect the intake boot, flexing it and checking the underside where cracks often hide, plus the clamps at the MAF and throttle body.
  4. Pull the oil filler cap at idle. If idle changes sharply or the cap sucks down hard, the PCV system needs attention.
  5. Smoke test the intake tract with an EVAP smoke machine at 0.5 psi. Escaping smoke pinpoints the leak in minutes.
  6. With the engine idling, spray carb cleaner or feed propane around suspect joints. An rpm change confirms leak location.
  7. Inspect intake manifold seams, vacuum ports, and the brake booster hose for cracks, especially on plastic manifolds past 150,000 km.
  8. Clear the code, drive a full warm-up cycle, and recheck fuel trims to confirm the repair took.

Quanto costa riparare P2279?

I costi di riparazione di P2279 variano a seconda della causa principale e del tuo veicolo. Ecco le stime tipiche:

Riparazione Costo dei ricambi Costo della manodopera Stima totale Difficoltà fai-da-te
Replace cracked intake boot or hose €25–€90 €30–€80 €55–€170 Facile
Replace PCV valve and associated hoses €15–€120 €40–€150 €55–€270 Facile
Replace intake manifold gasket €40–€150 €250–€600 €290–€750 Professionale
Replace vacuum lines or brake booster hose €10–€60 €40–€120 €50–€180 Facile
Replace throttle body gasket €15–€50 €80–€180 €95–€230 Moderata

Prezzi stimati al March 2026. I costi variano in base alla regione, al veicolo e all'officina.

P2279 su veicoli specifici

P2279 si comporta in modo diverso a seconda del tuo veicolo. Seleziona la tua auto qui sotto per cause specifiche del modello, problemi noti e stime dei costi adeguate:

Ford

P2279 su Ford F-150 5.4L Triton 3V

2004-2010

The 5.4L 3V is well documented for split PCV hose elbows and cracked plastic intake manifolds around the coolant crossover. TSB 08-23-4 covers the PCV hose update.

Cosa causa P2279 su una Ford F-150 5.4L Triton 3V?

Ford F-150 5.4L Triton 3VSplit PCV hose elbow at the valve cover (superseded Ford part 3L3Z-6A664-BA)
Ford F-150 5.4L Triton 3VCracked plastic intake manifold at the coolant crossover
Ford F-150 5.4L Triton 3VTorn intake air tube at the throttle body clamp

Costo di riparazione di P2279 per Ford F-150 5.4L Triton 3V

Costi stimati per i proprietari di Ford F-150 5.4L Triton 3Vadeguato al rialzo rispetto alla media a causa dei prezzi dei ricambi specifici Ford

Riparazione Costo dei ricambi Costo della manodopera Stima totale Difficoltà fai-da-te
Replace cracked intake boot or hose €28–€99 €33–€88 €61–€187 Facile
Replace PCV valve and associated hoses €17–€132 €44–€165 €61–€297 Facile
Replace intake manifold gasket €44–€165 €275–€660 €319–€825 Professionale
Replace vacuum lines or brake booster hose €11–€66 €44–€132 €55–€198 Facile
Replace throttle body gasket €17–€55 €88–€198 €105–€253 Moderata

Prezzi stimati al March 2026. I costi variano in base alla regione, al veicolo e all'officina.

Volkswagen

P2279 su Volkswagen Golf 2.0 TSI (EA888 Gen 2)

2008-2014

The EA888 Gen 2 valve cover integrates the PCV diaphragm. When it tears (very common past 100,000 km) you get a huge vacuum leak and instant lean codes. Full valve cover replacement is the fix.

Cosa causa P2279 su una Volkswagen Golf 2.0 TSI (EA888 Gen 2)?

Volkswagen Golf 2.0 TSI (EA888 Gen 2)Ruptured PCV diaphragm inside the valve cover (part 06H103469T)
Volkswagen Golf 2.0 TSI (EA888 Gen 2)Cracked turbo inlet elbow or MAF-to-turbo hose
Volkswagen Golf 2.0 TSI (EA888 Gen 2)Leaking intake manifold runner (IMRC) flap seals

Costo di riparazione di P2279 per Volkswagen Golf 2.0 TSI (EA888 Gen 2)

Costi stimati per i proprietari di Volkswagen Golf 2.0 TSI (EA888 Gen 2)adeguato al rialzo rispetto alla media a causa dei prezzi dei ricambi specifici Volkswagen

Riparazione Costo dei ricambi Costo della manodopera Stima totale Difficoltà fai-da-te
Replace cracked intake boot or hose €30–€108 €36–€96 €66–€204 Facile
Replace PCV valve and associated hoses €18–€144 €48–€180 €66–€324 Facile
Replace intake manifold gasket €48–€180 €300–€720 €348–€900 Professionale
Replace vacuum lines or brake booster hose €12–€72 €48–€144 €60–€216 Facile
Replace throttle body gasket €18–€60 €96–€216 €114–€276 Moderata

Prezzi stimati al March 2026. I costi variano in base alla regione, al veicolo e all'officina.

BMW

P2279 su BMW 3-Series N54/N55 (E90/E92)

2007-2013

N54 plastic charge pipes crack at the throttle body flange, especially with a tuned car. N55 valve cover CCV/oil separators fail and pull crankcase vacuum into the intake.

Cosa causa P2279 su una BMW 3-Series N54/N55 (E90/E92)?

BMW 3-Series N54/N55 (E90/E92)Cracked OEM plastic charge pipe (N54, part 11617599290)
BMW 3-Series N54/N55 (E90/E92)Failed oil separator in the valve cover (N55)
BMW 3-Series N54/N55 (E90/E92)Perished brake booster vacuum hose at the check valve

Costo di riparazione di P2279 per BMW 3-Series N54/N55 (E90/E92)

Costi stimati per i proprietari di BMW 3-Series N54/N55 (E90/E92)adeguato al rialzo rispetto alla media a causa dei prezzi dei ricambi specifici BMW

Riparazione Costo dei ricambi Costo della manodopera Stima totale Difficoltà fai-da-te
Replace cracked intake boot or hose €33–€117 €39–€104 €72–€221 Facile
Replace PCV valve and associated hoses €20–€156 €52–€195 €72–€351 Facile
Replace intake manifold gasket €52–€195 €325–€780 €377–€975 Professionale
Replace vacuum lines or brake booster hose €13–€78 €52–€156 €65–€234 Facile
Replace throttle body gasket €20–€65 €104–€234 €124–€299 Moderata

Prezzi stimati al March 2026. I costi variano in base alla regione, al veicolo e all'officina.

Toyota

P2279 su Toyota Camry 2.4L 2AZ-FE

2002-2009

The 2AZ-FE is generally leak-tight, but the ribbed intake air connector between MAF and throttle body hardens and splits along the convolutions past 200,000 km.

Cosa causa P2279 su una Toyota Camry 2.4L 2AZ-FE?

Toyota Camry 2.4L 2AZ-FECracked intake air connector (Toyota part 17881-28110)
Toyota Camry 2.4L 2AZ-FEFailed PCV valve at the rear of the valve cover
Toyota Camry 2.4L 2AZ-FELeaking throttle body gasket after a recent cleaning service

Costo di riparazione di P2279 per Toyota Camry 2.4L 2AZ-FE

Costi stimati per i proprietari di Toyota Camry 2.4L 2AZ-FEadeguato al ribasso rispetto alla media a causa dei prezzi dei ricambi specifici Toyota

Riparazione Costo dei ricambi Costo della manodopera Stima totale Difficoltà fai-da-te
Replace cracked intake boot or hose €23–€81 €27–€72 €50–€153 Facile
Replace PCV valve and associated hoses €14–€108 €36–€135 €50–€243 Facile
Replace intake manifold gasket €36–€135 €225–€540 €261–€675 Professionale
Replace vacuum lines or brake booster hose €9–€54 €36–€108 €45–€162 Facile
Replace throttle body gasket €14–€45 €72–€162 €86–€207 Moderata

Prezzi stimati al March 2026. I costi variano in base alla regione, al veicolo e all'officina.

Honda

P2279 su Honda Civic 1.8L R18A

2006-2011

R18 owners commonly find the PCV hose to the intake manifold hardens and cracks at the fitting. The IMRC gasket on the lower intake also leaks by 150,000 km.

Cosa causa P2279 su una Honda Civic 1.8L R18A?

Honda Civic 1.8L R18AHardened PCV hose cracking at the manifold barb
Honda Civic 1.8L R18ALeaking IMRC gasket between upper and lower intake
Honda Civic 1.8L R18ASplit intake tube at the accordion section behind the airbox

Costo di riparazione di P2279 per Honda Civic 1.8L R18A

Costi stimati per i proprietari di Honda Civic 1.8L R18Aadeguato al ribasso rispetto alla media a causa dei prezzi dei ricambi specifici Honda

Riparazione Costo dei ricambi Costo della manodopera Stima totale Difficoltà fai-da-te
Replace cracked intake boot or hose €21–€77 €26–€68 €47–€145 Facile
Replace PCV valve and associated hoses €13–€102 €34–€128 €47–€230 Facile
Replace intake manifold gasket €34–€128 €213–€510 €247–€638 Professionale
Replace vacuum lines or brake booster hose €9–€51 €34–€102 €43–€153 Facile
Replace throttle body gasket €13–€43 €68–€153 €81–€196 Moderata

Prezzi stimati al March 2026. I costi variano in base alla regione, al veicolo e all'officina.

Questi codici compaiono spesso insieme a P2279 o indicano problemi correlati:

Domande frequenti su P2279

Can I tape up a cracked intake boot to get home?

Self-fusing silicone tape will hold for a day or two, but the crack keeps propagating with every vacuum pulse. A replacement boot is €25 to €90 and usually a 20 minute job with a screwdriver.

Why does my car idle rough but drive perfectly fine on the motorway?

Manifold vacuum is highest at idle when total airflow is lowest, so a pinhole leak makes up a big percentage of the air the engine sees. At cruise the same leak is a rounding error and closed-loop trims mask it.

Will P2279 damage anything if I keep driving?

The engine won't self-destruct, but sustained lean running raises combustion temps and cooks the catalytic converter over weeks. A new cat is €400 to €1500, so spending €50 on a hose is the smart play.

Can a dirty MAF sensor cause P2279 on its own?

No. P2279 specifically flags air the MAF never saw. A contaminated MAF typically sets P0101 or generic lean codes. Clean it with dedicated MAF spray if it looks oily, but don't stop looking after that.

Does a loose oil cap actually trigger P2279?

On many engines, yes. The oil cap seals the PCV circuit. If it's missing, cross-threaded, or the rubber seal is flat, you pull unmetered air straight into the crankcase and into the intake.

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Esegui la scansione della tua auto con Skanyx per diagnosticare P2279

La tua auto ha registrato P2279. Skanyx lo legge con qualsiasi adattatore OBD2 Bluetooth standard, ti dice se puoi continuare a guidare in sicurezza e mostra la fascia di riparazione di €50-€750 così conosci la cifra prima che un'officina ti faccia un preventivo.

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