Weasel Damage or Mass Air Flow Sensor?

Hello.

It's about a Bora with a 1.9 TDI engine (ALH). It has 170,000 kilometers (approx. 105,000 miles) on it. The turbocharger is leaking oil, but otherwise, everything has been okay so far.

Yesterday, when I was trying to get onto the highway, I suddenly experienced a loss of power. The diagnostic display showed that when I pressed the accelerator, the boost pressure initially increased, but after a few seconds, it dropped to around 0.6-0.8 bar. Today, in daylight, I found a partially chewed vacuum hose that connects to the vacuum actuator on the turbocharger. I replaced the hose, and the rest appeared to be in good condition. I read the error codes, and the signal from the mass airflow sensor (MAF) was too low. I cleared the codes, drove the car, but the power issue persisted. I read the codes again, and there were no errors in the engine control unit (ECU). I drove the car with the diagnostic tool connected and monitored the live data. In the idle measurement block 21, the value was 390. When I applied full throttle, it initially reached 800, but then dropped to around 580-610.

Does anyone have any advice?

Regards,

Paul.

"And where are your log files? We would definitely like to see what your quantity limits, air mass, and LD values are. So far, the experts here haven't found any significant clues."

Quote:

At full throttle, it reaches 800, but then drops to approximately 580-610.

I'd say there's a 75% chance it's an LMM.
If it's still the first one, I wouldn't try to fix it for long, I would just replace it. Strangely enough, it sometimes shows correct values for a short time when you first accelerate.

Should I watch MWB 21, or is there somewhere else I can watch more?

The LMM (likely referring to a mass airflow sensor) was replaced once, at 100,000 kilometers.

Biddeschön 3. Gang Vollgas. MWB 3

http://www.polo2f.privat.t-online.de/MWB3.CSV