1998 Volkswagen TDI

Engine Performance problem
1998 Volkswagen TDI 4 cyl Front Wheel Drive Manual 115000 miles

My 1998 VW Beetle TDI 1.9 is very sluggish when I excellerate to pull out. It seems to lack excelleration power until it reaches a steady speed. The check engine light comes on shortly after I start it also and stays on until I shut the car off.
I am thinking it may possibly be a sensor causing the problem.
Just looking for a little feedback on what is causing this to happen. Any advice on a solution to this problem would b greatly appreciated.
April 13, 2010.

Have the computer scanned for code/s-you have a problem within the engine management system that caused the CEL to come on-this is your starting point to finding out what's going on.

Apr 13, 2010.