Turbocharger pressure problem with ALH engine

Hello. I hope you can help me again.
I'm driving a Golf IV with the (still unmodified) 90hp ALH engine. Mileage: 99,000 km.
Recently, I installed a boost gauge (and I'm reasonably sure it was installed correctly), and it's showing the following readings:
"When I accelerate fully, then release the gas and immediately accelerate again, I experience overpressure spikes up to 1.5 bar (the maximum reading on the gauge). The needle usually stays at that point for about 0.5 seconds before dropping back to a very low pressure of around 0.65-0.7 bar. Then the pressure rises again to 0.95 bar. At 3000 RPM, I briefly reach 1 bar." Later, the pressure drops back to approximately 0.95 bar.
Actually, I'm supposed to set the pressure to 0.9 bar and have an overshoot of up to about 1.3 bar.
If I accelerate slowly, I also don't experience any pressure spikes above 1.3 bar.
The regulated boost pressure always remains between 0.95 and 1 bar.
I haven't experienced that situation in emergency mode before.
What's wrong with me, and what can I do about it?
Thank you for your help...
Best regards,
Bernd

Your problem is not an isolated case; you are just one of a thousand.

as 1. VTG makes things easier.
2. Check all vacuum hoses for leaks.
3. The replacement turbocharger boost control valve.

but please search in the search functions, we've already discussed this a dozen times .

It's often said that a faulty mass airflow sensor (MAF) can also affect the boost pressure.
Can this be ruled out as a cause for my problem? I'm still using the original one after almost 100,000 km. Shouldn't it have broken down by now? I don't want to just waste the money, though...

It is often said that a faulty mass airflow sensor can also affect the boost pressure.

I haven't heard that before.


Can this be ruled out as a cause for my problem? I'm still using the original one after almost 100,000 km. Shouldn't it have broken down by now? I don't want to simply waste the money, either...

there are also some that last
'In my ALH, it consistently delivered above-average performance until I sold it with 190,000 km on the odometer.'

My A4 LMM (mass airflow sensor) now has 262,000 kilometers (approximately 163,000 miles) on it and is still producing readings around 900-1050.

Check your if it stays consistently above 850 when running at 4/5 full throttle, then...
Can you disable the "getrosst" feature and make your VTG (variable transmission gear) function normally?