engine bogs down at 2500 rpms

Hey guys Im new to the forum and couldnt find any reliable info to help e with my problem...
I have a 2001 TDI That was running like a champ. but recently the power has steadily declined. If I reach 2500 rpms in gear 3 or 3000 in 4 there's a noticeable stutter... its almost as if the engine couldn't breath. My first thought was the MAF so replaced it. still no help secondly we cleaned out the intake and got rid of all of the carbon build up. still no long term help. I thought about doing the egr valve bypass but the kit seems like something I couldnt do without help and a friend of mine told me that we could temporarily block it with a BB or something to see if the issue was the egr valve. Still no change. I replaced the fuel filter and air filter recently as well... I'm at a loss. I'm not an engine guy so my knowledge is limited. anyone have any thoughts

Intake could possibly be plugged up.

we cleaned it out last month...

have you scaned for codes?

I did but it gave an error in the scanner like the fuse was bad or something so it wouldn't show a code...

I pulled the whole egr valve off (not any easy task for a man with big hands). It was disgusting! The intake past it was even worse. I suspect the guy who told me he cleaned the intake didn't really do much because it was a month ago and today the pipe was as least 40% blocked. It helped once I got it back together. Now it seems to breath much better and didn't really seem to big down until much higher Rpms. I imagine I need to have the intake manifold removed and fully cleaned. If the pipe just past the egr valve was as bad as it was I can't begin to think how nasty it is further in. My question is how difficult of a job is removing the entire manifold?

I would say it;'s not that bad, I also have BIG hands but I don't have the egr cooler so not sure how in the way that might be. I just feel for the bolts, 6 of them and they're 6mm allen heads.

It can be easier of you pop off the little heat shield for the intake pipe that's bolted to the exhaust manifold, maybe the bracket for the turbo oil feed pipe too.

Turbo vanes could be sticking. Check that turbo actuator is free and capable of full smooth motion using something like a mityvac. Full motion is aprox 3" Hg to aprox 18"Hg.
Just got done dealing with this same issue.