B6 S4 low on power


I am getting loss of power below 5k rpm.
Fells really sluggish below, but at 5k it feels like an 1.8t when the turbo kicks in.

No error codes stock car. Just had it serviced

What was done in the last service. When was this done and what are the current mods (if any)

It was oil service at audi dealership.
Car is completly stock.

Fuel filter, spark plugs and air filter was not changed. Would this make such a big impact?

Fuel filter might but you would probably see other issues as well. Still that would be a thing to change. The B6 can suffer from damaged cats. This can lead to issues of poor performance.

Do you have Vag-Com? Or a similar tool?

I got vagcom.
Was planning on gutting the cats soon, they do more harm than good anyways

Yeah the cats can get damaged and just cause all kinds of issues.

Do you know how to log the car. Do a log in say 3rd gear. Log throttle / RPM / Ignition and correction. That would be a good start to see whats up. Then you should be able to just post the log here.

With the engine off, stick you hand down between the front of the intake manifold and the core support to move the intake manifold flap. It should move easily and if it doesn’t then you need to take the sleeve off and grind it open to allow the variable length intake manifold flap to move correctly.

Your flap might be stuck in the high rpm setting from buildup over time. Ideally the engine should pull vacuum on the flap at low rpms to move it to the low rpm setting to increase lower end torque. The intake manifold flap is not a monitored component of these engines so this will not set a fault code or check engine light.