Who is familiar with OBD tuning?

Hello,

Does anyone have experience with OBD tuning?

According to some suppliers, this should work for an AJM engine in a Passat PD with 85 kW (manufactured in 06/99, but a 2000 model).
Cost: approximately 250-270 euros.
TÜV extra, approximately 250 mosquitoes.
I once got a quote.
You can get the original files on CD, but unfortunately, the modified versions are not available.

How difficult is it to accomplish something like that?

Can VW workshops secure and download the original log files from the engine control unit (ECU), and also install other log files?

Shouldn't it be the case that something fails if it has problematic 'tolerances' from the factory?

Background: NONE!!! REALLY, NO ONE IS FINDING ANY PERFORMANCE LOSS!

Maybe someone here knows a solution.

Unfortunately, I don't have a login, I'm not familiar with data reading, and I'm no longer willing to spend more money on taking it to workshops.

I'm curious to see what the forum will be like.

So long

Thorsten.

(P.S. The mileage on my Passat Comfortline is now 105,000 km. Since I bought it with 22,000 km, I've been experiencing a loss of power!)