TDI LMM: Tuning Issues on AJM Engine?

Good morning, everyone.
I'm new here and I already need your collective expertise to solve a very specific problem.
The LMM (lambda sensor) on my chip-tuned AJM engine is slowly starting to fail.
The target values are just at the limit, and when running at full load in 6th gear on the highway, the instantaneous fuel consumption is only 14.5 liters, compared to 16.7 liters before. The turbo boost pressure is okay. The loss of power starting at 3000 RPM is very noticeable.
A new lambda sensor (oxygen sensor) from VW costs around 300 Euros. On eBay, someone is offering just the sensor as a new part from Bosch for 109 Euros.
Okay, here's my problem:
I bought the sensor from him with the Bosch part number 0 280 217 121, but I received a different sensor. While it fit and worked fine in the lower RPM range (up to 3000 RPM), it severely restricted performance above that.
The sensor also has another part number: Bosch F 00C 2G2 027 (original), which he cannot supply. He has now offered me the Bosch F 00C 2G2 047, which is used in the 2.5 V6 TDI.
What do you think about this? Do you think it's a good idea, or not?
Or have I perhaps overlooked another potential source of the problem (the air filter has already been replaced)?
Thank you very much.
Mick.

Is the Bosch 00C 2G2 047 pump-injector compatible with engines producing 110 kW / 150 hp?
I can't look it up right now, but that number sounds very familiar to me!

If so, then take that one!

Alternatively, you can also use the one from Pierburg! (available at Mercedes for 70 euros).

It's working perfectly for me!

How many kilometers have you driven without and with modifications?
Where did you have it done? How much more power does it have?

Morning, Dan.jel.
I've driven about 90,000 kilometers since the tuning.
It's from the company Koch (Chiptronic) in Schopfheim, near Lörrach. I came across them by chance, and I was convinced by their service and price (e.g., they offered an extensive test drive with their development platform, etc.).
Power measured at 114 kW and 385 Nm of torque. So far, no problems other than the mass airflow sensor (MAF). I also had a K&N filter installed, but I removed it because it supposedly allows too many fine soot particles from the exhaust gas recirculation system to pass through in common rail diesel engines. You can clearly see the burnt-on particles on the old MAF sensor.
It would be great if someone else could find a precise answer to my problem.
Best regards,
Mick.

Quote:

So far, no problems at all, except for the mass airflow sensor (MAF). I also had a K&N filter installed, but I removed it because it supposedly lets too many fine soot particles from the exhaust gas recirculation system through in common rail diesel engines. You can clearly see the burnt-on particles on the old MAF sensor.

Please don't post any nonsense here.

Here, you can find out which mass airflow sensor belongs to which vehicle or Bosch part number.
http://www.bosch-automotive.com/ecat-online