TDI PD 115 PS: Power Loss with Chip Tuning

I've been getting a fuel consumption of 8.5 liters per 100 kilometers for the past month.
Normally, after chip tuning, a normal driving style resulted in a fuel consumption of 6.5 liters for a period of 3 years.
Now it's rusting during normal driving.
When I press the accelerator, it runs smoothly and accelerates without any jerking. However, it reaches its maximum speed at around 180 km/h.
Normally, 210 km/h according to the speedometer.
He runs as if he were resisting something at top speed.

Today, I had the Bosch service replace the mass airflow sensor (MAF sensor) for 87 euros, but nothing has changed.
They then said that Turbo would have to undergo a 2-hour test program.

I then went to Volkswagen.
They either meant "turbo".
or the fuel filter, which has only been used for 30,000 kilometers.
or boost pressure regulator.
or catalyst.
I'm now wondering what it could be. I don't have an appointment with the mechanic until next week.
"But I don't want to drive around all the time with a fuel consumption of 8.5 liters per 100 kilometers."
What do you think?
greetings
chris

Hi,
Okay, I'd say it's probably Kat. In my opinion, she's the only reason your consumption has increased so much.

I'm going to my colleague's workshop now to take a look at the catalytic converter.
Well, it's not the cheapest solution, but hopefully it's better than a turbocharger.
Thank you in advance.
chris

We had a similar problem once, and they used a pressure washer to flush the cat out from the other side.

Okay, the catalytic converter is fine, there are no issues, everything is working properly.
After the turbo, there's some oil in the hose.
"Could be turbo damage? My friend suggested I take it to a VW or Bosch service center to have the boost pressure checked and the compression measured."

Then we noticed that oil was leaking around the top of the engine, apparently from the pressure relief valve.

I'm planning to buy a new fuel filter tomorrow and replace it, but I changed it 20,000 km ago.

The error memory shows no entries.

greetings
chris

'Black smoke indicates insufficient boost pressure. This could be caused by a sticking or malfunctioning VTG (variable turbine geometry).'

Read the relevant technical articles here and try to find out values for things like charging pressure, etc.!

ok, thank you, I will.

Yay, bug found!
I made an appointment for a charge pressure test at VW for tomorrow.
I was just about to go check on the car again.
"I then saw two cracks, each 1 cm long, running across the intercooler housing."

Then I fixed the tear with tape, and sure enough...
It's going over 200 again, and it's pressing you back into your seat as it accelerates, just like it always does.
I'm going to order the hose from VW tomorrow. It probably won't be cheap, but it will be cheaper than the turbo.

The only thing that makes me suspicious is that oil leaked from the top left of the hose connection on the ATJ engine, and as a result, the engine oil pan was full of oil.
Is that a square tube, and is its length 5 cm?
I might replace this one as well.

Thank you for the tips.

Sure, here's the translation:

"There's probably still a small detail that needs to be corrected."
Tonight, after the great weather, I drove home.
I then overtook a car and was going about 160 km/h. I kept pressing the accelerator, but the engine speed just kept dropping.
140
120.
It would only start again if I gave it a little bit of gas.
"But when I floored it, it felt like the engine had stalled."
I was driving through the city at 50 km/h, but as soon as I pressed the gas pedal harder, nothing happened.

Okay, I've checked all the hoses again, and everything seems to be fine.

I opened and closed the release lever a few times, then I drove off, and everything was back to normal.
Now it's running smoothly again.
Does the valve have any issues? Can anything be cleaned inside?
Best regards.
chris

emergency mode??

hi no, not emergency mode. he's driving at 100, or 50, or 140 (km/h).
It's like he's not getting enough air.
and in the event of a malfunction, a message will appear in the error memory.
"VW told me to monitor it and, if it happens more often, to check the boost pressure regulator or something like that."