P2279 VW/Audi Fault Code: Diagnosis & Repair

Disclosure: This post may contain affiliate links, meaning when you click the links and make a purchase, we receive a commission.

P2279 VW/Audi Fault Code: Intake Air System Leak

When you receive a P2279 code on your Volkswagen or Audi, it will read out “Intake Air System Leak” or “Leak in Air Intake System”. Unfortunately, this engine code is not specific to any Volskwagen/Audi engine or vehicle. When this code pops up, it indicates that there is an air leak occurring in the engine. There are many sensors that regulate the amount of air that is going in and out of the engine such as a Mass Airflow Sensor (MAF), air intake temp sensor, and o2 sensors. When too much air is exiting the engine, the PCM will pick this up and return a P2279 engine code indicating an engine leak. Without correct AFRs, the engine’s timing and performance will be off until fixed.

Can you still drive with a P2279 VW/Audi Fault Code?

Yes, but if the leak is major, it will be very difficult to drive. When this happens, engine stalls and surges will be very common and will be difficult to drive consistently. We would rate this engine code as moderately severe. The reason being is what we just stated, if it happens to be a major leak and is ignored, it could lead to major engine damage. So our advice, if you are DIY savvy, would be to tackle the causes from the top to the bottom and it should clear the code. If you would rather take it to a shop, it could be an expensive diagnosis and repair.

P2279 VW/Audi Symptoms

• Check Engine Light (CEL) or Malfunction Indicator Light (MIL) illuminating
• Engine stalls or surges
• Rough idle
• Engine misfires and P0300 – P0310 fault codes
• Lean AFR conditions
• Poor engine performance
• Hissing sound if the leak is major

Causes of P2279 Engine Code for Volkswagen’s or Audi’s

• PCV valve failure
• Faulty N79 valve
• Intake manifold runner out of specification
• Air intake tube leaking air
• Intake air temp sensor leak
• Throttle body leak
• Vacuum hose leak
• Brake booster hose leaks
• Failing fuel injector seals

How to Repair a Volkswagen or Audi with a P2279 Engine Code

Our advice would be to clear all codes first and test drive for a little bit to see if the codes pop back up. If so, the list below is what we would start with from most likely to cause the P2279 VW code to least likely. Before getting into the guides below, we want to preface that all of the replacement parts and DIYs are for a Volkswagen/Audi 2.0T engine because it is the most popular VW/Audi engine.

Replace the PCV Valve/Check the N79 Valve

This is one of the most common causes of a P2279 engine code. A PCV, Positive Crankcase Ventilation, valve captures fuel vapors and recirculates them into the intake system to be burned off before going into the environment. Essentially, a PCV valve controls the emissions of a vehicle. The N79 valve, or the heating element of the PCV valve system, vaporizes condensed water in the blowby gasses preventing ice blockage in the PCV system. Unfortunately, this is a common failure on many Volkswagen and Audi engines. However, it is a pretty straightforward DIY that would save you on labor costs if you decide to replace it on your own.

Buy Here: Volkswagen/Audi 2.0T PCV Valve
DIY Difficulty: Easy

Check the Intake Manifold Runner and Intake Tube

A common cause for the P2279 engine code is the intake runner position sensor failing. This is most common on 2.0T and 2.0TDI Volkswagen and Audi engines. If the P2279 engine code is accompanied by a P2015 engine code, 9/10 it is a faulty intake manifold position sensor. An intake manifold supplies fresh air to the engine’s cylinders. Air is brought in through the air intake, through the throttle body, and into the intake manifold before going to the cylinders to ensure proper AFRs. If you aren’t up for the DIY route, a shop would likely charge around $650 to replace the intake manifold.

The tube coming off of the air intake is another common place to have leaks, but it is easier to diagnose if that is the issue. You can simply put your ear up to the tube while the engine is running and listen for a hissing noise.

Buy Here: Volkswagen/Audi 2.0T Intake Manifold
DIY Difficulty: Intermediate

Check the Intake Air Temp Sensor

If after checking the intake manifold and ensuring it isn’t the issue, the next step would be to check the intake air temp sensor. An intake air temperature sensor is located somewhere on the intake tube and it determines the temperature in the tube and relays it to the ECU to ensure proper AFR’s. Luckily, it is a rather inexpensive part and labor should be quick and easy. If you plan to DIY it, you would save around $100, mainly due to labor costs.

Buy Here: Volkswagen/Audi 2.0T Intake Air Temperature Sensor
DIY Difficulty: Intermediate

Check for Throttle Body Leaks

The throttle body has a gasket that is in between the throttle body and the intake manifold. If this gasket happens to fail, it could cause a P2279 engine code. Located between the air intake and intake manifold, the throttle body regulates airflow into the engine. Luckily, a throttle body gasket isn’t expensive and it is rather easy to get to if it needs replacing. However, a throttle body itself is not cheap. So if you are looking to take it to a shop to replace the throttle body, you’ll be looking at a bill of around $500.

Buy Here: Volkswagen/Audi 2.0T Throttle Body
Buy Here: Volkswagen/Audi 2.0T Throttle Body Gasket
DIY Difficulty: Difficult

Check for Vacuum Hose Leaks

From this cause down is where it starts to get more difficult to diagnose. A common engine code that would accompany a P2279 when it comes to vacuum leaks is P0171. Vacuum hoses create suction and bring air into the engine. The main hose to look out for when it comes to vacuum hose leaks is the hose that connects the vacuum pipe to the vacuum pump. Diagnosing and replacing vacuum hoses is not an easy or cheap endeavor. It’ll likely run you up about $300 depending on how quickly they can pinpoint the issue.

Buy Here: Volkswagen/Audi 2.0T Vacuum Hose
DIY Difficulty: Difficult

Check for Brake Booster Hose Leaks

The brake booster hose or line is found between the master cylinder and the brakes, which allows the brake booster to function properly. A brake booster assists a vehicle’s brake performance. Without a functioning brake booster hose, the brakes could be in danger causing an unsafe driving environment. Unfortunately, the price can fluctuate when it comes to diagnosing and replacing a brake booster hose leak. We’ve seen anywhere from $400 – $1,000 all depending on vehicle and labor rates.

Buy Here: Volkswagen/Audi 2.0T Brake Booster Hose
DIY Difficulty: Intermediate

Replace the Fuel Injector Seals

Lastly, pretty unlikely but possible, fuel injector seals can cause a P2279 engine code. Fuel injectors pump fuel into the engine’s cylinders which assists in engine combustion. The fuel injector seal or O-ring seals the injectors to the fuel rail and intake. Therefore, if a seal has busted or deteriorated from the engine’s heat, it could cause air to leak out of the engine. We’ve supplied replacement fuel injectors and seals or O-rings below because it is a wide variance in cost. If you are looking to replace a fuel injector versus changing out the seals and O-rings, you’ll be looking at a cost of around $600.

Buy Here: Volkswagen/Audi 2.0T Fuel Injector Kit
Buy Here: Volkswagen/Audi 2.0T Fuel Injector Seals and O-Rings
DIY Difficulty: Intermediate

P2279 Volkswagen/Audi Conclusion

We hope the information above has alleviated the P2279 VW/Audi engine code. You can drive a vehicle that has this code for a little bit depending on how major of an air leak is present. However, we would highly advise addressing the issue as soon as possible because more problems could arise if it is ignored. This is one of the harder fault codes to diagnose, but we would say most of the time it has to do with the PCV valve. If that doesn’t do the trick, then it gets much trickier from there.

Please let us know in the comments if this guide has alleviated the code and what was causing the code for your vehicle in the comments below. This will assist future readers with this engine code as well. Lastly, if you need assistance in finding guides or replacement parts for a different engine, let us know in the comments below and we will assist in any way we can.