TDI Engine: AHY 4-Cylinder (111kW)

Translated on 24-10-2026, 14:30.

Hi everyone, I have a question for all the diesel experts. Our T4 TDI doesn't have the same power it used to (75,000 km). It only rarely reaches 200 km/h. A new MAF sensor was installed only 3 months ago. I recently removed the K&N filter because I've heard that it can damage the MAF sensor (let's not start a discussion about that thing!!!

). In my A3, the engine started misfiring again after an oil change, so I replaced the filter with the original one. Then I cleaned the MAF sensor and the intake air temperature sensor, and it's running smoothly again. But it's not that easy with the T4. It has a different type of MAF sensor that's encapsulated, so you can't easily access the sensor itself. Is there a way to clean it, or what could be the cause?

Translated on 24-10-2026, 14:31.

Does anyone have any experience with that?

Translated on 24-10-2026, 14:32.

davidshoes wrote:

What else could be the cause?

-> Error database.