p0299 turbo underboost and smoke

Just wanted to ask a few questions , i have a 03 vw golf tdl with 150k milles , love the car but latley i had a lot of problems with it , check engine light came in (code p0299 turbo charger under boost) and when i drive under load a lot of black smoke behind me , till the car goes into a limp mode , any suggestions where to look first to check for problems , this is my first tdi so iam not that familiar with it , any help will be appreciated thank you

Hi, welcome to TDI club.

Take a look at the link in my sig for troubleshooting low power / limp mode.

Also, have you changed your Timing Belt?

Thanks.

timing belt was done less then 15k milles ago

By a trusted mechanic?

are you sure the timing was correct on it?

thanks for info , i have a question , i disconnected the muff and i had no black smoke but car was in limp mode , is that normal? when i pluged it in again same problem happens lots of black smoke on acceleration , and limp mode after a while , also i noticed that around 2 to 3 k rpms car jerks a little like looks for power and then just goes thanks for your help .
And a timing belt was done at local dealership

Are you certain the car was in limp mode when you unplug the maf?

What makes you say that it went into limp mode?

the engine was off when i unplugged the maf , when i started the car and went for a drive the turbo was not going on , i pulled over and connected maf , and tubro was going on a lot of black smoke from the tail pipe , and it was hesitating aroung 2k rpms

I have never heard of the turbo not running at all with the maf unplugged.

Carefully check all your turbo plumbing. Sounds like a split pipe or a connection came apart. Have you ever checked your snowscreen? Do you have a buddy that you could swap in a known good MAF?

no i will check snowscreen tomorrow morning ( just looked up what it is ), today i noticed a oil leak under the passenger front tire dont know where its comming from , and i dont know anyone in the area that has a tdi , i will try to check all turbo pluming , thank you for your help