Loss of power between 2800-3000 rpm

I have a 2001 TDI Golf, 5 speed manual 1.9L that is losing power periodically when trying to get on the highway. It usually happens in 4th gear between 2800-3000 rpm around 60mph. I've done some research and it tells me different things, mainly with vanes or the acuator. My CEL comes on and the code is PO234. The code will go out if I baby it in a couple days.

Any thoughts as to where I should start?

Thanks in advance!
Dan

Are you using vcds to look up the codes? If no find some one who has it...
Start with a log of group 11 (think its group 11) and go for a drive in third gear where it generally limps. Look for requested boost vs actual and see how far off the two are.. Could be a limp home mode issue if the boost is too high...
N75 output test using basic settings would help determine if the n75 is working right start with that..

Hooked it up to a vag and got code 16618. After researching this code it sounds like MAF. I just replaced it about 9 months ago. Wondering if it went bad?

Does the power come back right away if you turn the ignition off and then restart? If so, it's classic "limp mode" and a search will give you all the reading you need to get it straightened away.
Generally sticky vanes/actuator and/or a vacuum leak or maybe a faulty N75 valve.

2 dollar bet - stuck actuator

Simple solution: stay the hell below those RPMs!!!