Code P0299

Hi I'm relatively new to working on PD BHW engines so maybe you smart people can put me on the right course of action.
I converted my 2005 TDI Passat Wagon to a standard 5 speed a while back and in the process got a Mallone 1.5 tune done on it .It went really well for the last 30 K. The only drawback was excessive smoke on start up after the tune.
But just lately i've been getting a code P0299 and its been feeling like its low on power even when I don't have a check engine light accompanied by "Emission Workshop" on the dash. I realize when I do its gone into limp mode and is slow.
I have checked the obvious, intake leaks etc
My question is how do I check the N75 valve and how does one check the turbo output for possessively checking the boost pressure.
Second to that should I be pulling the intake and checking it / cleaning it,I have 230 K Km s on it, maybe blocked.
And if the cat was blocked would i get a code even after the re programming by Mallone.
Any of your thoughts and constructive opinions will be appreciated prior to diving in on this engine.
Thanks
Noel

http://wiki.ross-tech.com/wiki/index.php/16683/P0299/000665

You can check both the turbo and the n75 with a mityvac. An indispensable tool when own8ng a vw diesel. About $40 at an auto parts box store or amazon/eBay.

The vanes in your turbo are probably getting sticky, or when checking for leaks you may have missed one. Or the vacuum side of the tandem pump may be going, again you can check that with a mityvac vs spending a couple hundred dollars on a replacement.

Thanks Tdijarhead.
I presume one just taps into the vac line from the pump and observe the vanes being moved on the turbo or does that only happen when the N75 is energized
.What is the best procedure to follow in diagnosing this issue.

vacuum lines are the first thing to check, especially the connection to the actuator

The factory ecu calibration has an inherent flaw that manifests more readily as these cars age. The kermatdi tuning for BHW includes a fix for that factory flaw.

* I too have a similar problem, I have replaced all of the above mentioned and still have the damn emissions workshop beep, and engine light greet me at start up, even though my obdeleven says: no faults?
Is there a way to elimate the emissions workshop?

KERMA said:

vacuum lines are the first thing to check, especially the connection to the actuator

The factory ecu calibration has an inherent flaw that manifests more readily as these cars age. The kermatdi tuning for BHW includes a fix for that factory flaw.

Click to expand...

Care to elaborate on this? Or better yet show some actual proof of this, mysterious, so called flaw?

Check the fuel filter. When they start to clog up, it will choke the engine and it will feel like it's slowly loosing power.

Clogged air filter and/or inlet will also kill power.