P2279 error code

[dopeman1979]

If anyone can advise.... Getting this error code, when engine hot, and driven hard...
Next couple of days, if car driven normally for short distances, error code goes away.
Symptoms when code appears, engine revs drops randomly on idle. hissing noise from rear of engine
Again, when engine cold again, code goes away, no check engine light on dash.
engine is the 1.4tfsi CAXC ...102k miles
P2279 reffers to powertrain intaik air system leak
Any advise welcome

 

[ch1z64]

You might stand a better chance off getting an answer to your problem if you PM @Sandra ( admin ) and ask her to place in the Vcd's section off site .

 

[samuelh_888]

P2279 is a vacuum leak (as you say) - donyou have an aftermarket intake on the car? If so, make sure the jubilee clips are tight. Otherwise, check/replace your PCV and dipstick, check your oil filler cap is tight. If the issue persists there is a leak elsewhere... A smoketest would identify.

 

[Whodafunk]

This will be a leak AFTER the MAF (mass air flow sensor). It means the system is getting more air than the MAF is measuring entering the intake system. The ECU is constantly trying to achieve stoichiometry (lambda) of the correct air and fuel ratio. Since it’s getting extra unmetered air it will be increasing fueling to try and achieve the right mixture. It can only do this so much (by about 20%) before it triggers an EML. If you checked your long term fuel trim (measuring block 33 I believe) you would probably see a +20% figure at adaption (under load) and I suspect the figure at idle will be fairly normal.

The leak will be between the mass airflow sensor or throttle body and the manifold.

From a quick search, Check the following:
Leak between engine side of mass airflow sensor and air duct
Air duct leak engine side
Leak at intake air temperature sensor
Leak at throttle body
Intake manifold crack or leak
Disconnected or broken vacuum hose
Bad fuel injector seal at manifold
Leaky brake booster vacuum hose
Leak under dash at a vacuum operated device Stuck PCV valve
Stuck crankcase oil filler cap
Anything and everything connected to the intake manifold could potentially cause this scenario.

My money is on a bad PCV valve or a leak at your intake manifold

 

[dopeman1979]

cheers guys, will have a look