Problems with my Audi A3 TDI 110hp, engine code AGR

Hello everyone,
I'm having a small problem with my A3. At approximately 2500 RPM, it's producing a lot of black smoke. It also doesn't seem to have the same power as before. I used an OBD interface to log data and discovered that my boost pressure has decreased by 0.2 bar. Could this be the problem? And does anyone know what might be causing it? I would really appreciate any answers, as I'm worried about potential consequential damage from this issue.
Thank you.
Andi

Hello,

Does your EGR valve close properly, and are the intake air ducts airtight?

Best regards, Rainer.

Hello Rainer,
I have already pressure tested my intake hoses; I performed a leak test and they are all sealed. How can I determine if my EGR valve is closing properly?
Sure, here's the translation:

'Merce'
Andi

Hi,

There's only one thing to do: take it apart and see what's inside.

Regards,

Andy.

Thank you for the response.
How do I find it, and what does it look like? That would be really helpful. Thanks.

Andi

HeizoelpowerA3 wrote:

Thank you for the answer. wie finde ich den das Ding und wie schauht es aus.

Hello Andi,

If you find a canister that seems to be located randomly on the intake manifold, and there's a pipe running from the exhaust to the intake manifold that connects to said canister, then that is the EGR (Exhaust Gas Recirculation) system.
The designs vary in detail depending on the specific machine code.

Thank you for the quick response. I will try it out this weekend.
Mercè.

The best way to check if the AGR (Exhaust Gas Recirculation) system is working correctly is to hold your hand under the exhaust pipe while the engine is running with the AGR connected. There should be very little exhaust coming out at idle. When you disconnect it, you should hear a "click" with the engine running. After that, you should notice significantly more exhaust gases coming from the back of the car.

The whole situation sounds like it's likely due to a stuck EGR valve, because at -0.2 bar of boost pressure, there shouldn't be significant surging. However, if the EGR valve is stuck and pushing exhaust gases into the intake system, the pressure remains relatively constant because the pressure before the turbine's exhaust side is always greater than the pressure after the compressor side.