01 Jetta TDI Intermittenly Losing 50% of its power

Hey guys I have an 01 Jetta TDI 130k miles and Im having an intermitten Problem that happens every now and then. The car is 100% stock and occasionally the car just feels very sluggish like its lost 50% of its power or like the Turbo has stopped spooling.Car has the Factory Exhaust Cat and Muffler.I drove the car home 15 miles 2 days ago and it was doing this and when I came to a redlight I opened the window,revved the engine to hear the turbo spool and I did not hear it spooling at all.But 6 hours later the next morning I went out started it up the turbo was spooling just fine and the car ran perfect all day..?Whats up with this I am a new TDI owner but I am NOT new to cars at all.I read on one thread about the turbo getting clogged with carbon and using Easy Off cleaner to dislodge the carbon but I didn't read very far into that 10 page thread.Please post up your knowledge.Thanks alot.!

Jeff

Please follow the "low power / limp mode" thread in my sig.

It has instructions on how to troubleshoot the source of this problem and then how to fix it.

Thanks.

To be honest, that's a test I've never had to do.

My understanding was that most people put vacuum on the rod to test how much vacuum is required to move it.